This allows observation of moving direction in event displays.
Also support for ignoring track endpoints introduced in AliHelix to
allow correct display for very long tracks together with observed hits.
+18-mar-2006 NvE Support for display of selected track array introduced in AliHelix.
+ Also copy ctor of AliHelix made complete for new datamembers.
+22-mar-2006 NvE Line attribute selections for displays extended in AliHelix.
+20-apr-2006 NvE Several small modifications to prevent gcc warnings.
+10-may-2006 NvE Distance determination between tracks and/or jets introduced in
+ AliTrack and AliJet.
+ Also compiler warnings activated for overloaded virtuals in installation
+ script for AMD Athlon in the /scripts sub-directory.
+22-jun-2006 NvE Linear track storage facility introduced in AliSignal to enable
+ a lightweight signal <-> track backward linking facility instead of
+ the elaborate signal slot related links.
+ Also the functionality of AliTrack::AddSignal extended with specific modes.
+ Double_t replaced by Double32_t in Ali3Vector.h, Ali4Vector.h and AliBoost.h
+ and fDresult suppressed for I/O streaming. This will reduce the produced
+ output filesize.
+21-jul-2006 NvE AliSample extended for computation of median.
+12-sep-2006 NvE Memberfunctions GetNslots and AddNamedSlot introduced and various
+ modifications made in AliAttrib and AliSignal to overcome a ROOT
+ feature which always sets the size of TArray objects to a default
+ of 16 when reading these objects back from a file.
+ The modified AliAttrib and AliSignal don't rely on a GetSize()
+ anymore, but determine the number of stored values from the
+ actual array contents.
+19-sep-2006 NvE Accuracy problem solved in Ali3Vector::GetOpeningAngle.
+20-sep-2006 NvE AliSample::GetMedian corrected for empty or single value arrays.
+25-sep-2006 NvE AliSample extended with memberfunction GetSpread() and also
+ support for providing minimum and maximum values introduced.
+12-oct-2006 NvE New memberfunction GetNsignals introduced in AliJet and jet
+ ordering w.r.t. number of signals added in AliVertex.
+19-oct-2006 NvE AliJet::GetNsignals modified to prevent double counting of
+ multiple occurrences of the same signal.
+24-oct-2006 NvE AliJet and AliVertex extended with ordering w.r.t. charge.
+26-oct-2006 NvE Energy/Momentum scale indicator introduced in AliTrack and AliJet
+ and support for chi2 and ndf datamembers removed from AliTrack.
+ The latter can be achieved in a more flexible way via the fit
+ details facility of AliTrack.
+07-nov-2006 NvE Default unit scale changed from cm to meter in AliPosition
+ and support introduced for user selectable unit scale
+ in retrieval of position coordinates, errors and distances.
+08-nov-2006 NvE User selectable unit scale introduced for retrieval of
+ physics parameters and distances in AliTrack and AliJet.
+ Also the track and jet sorting memberfunctions of AliJet
+ and AliVertex have been updated to use this new feature.
+ Also AliHelix has been updated to use this new feature and the
+ default meter metric scale.
+09-nov-2006 NvE AliCollider updated to use new standard 1 meter metric units
+ and generator parameters stored in a device named "AliCollider".
+ Also beam/target datamembers removed from AliEvent and storage
+ of these beam/target parameters performed via a device named "Beam".
+10-nov-2006 NvE Bug fixed in AliHelix.cxx such that the original reference point
+ of the track itself is not modified when the user had specified
+ a different scale. Also GetLastPoint() used in AliHelix to obtain
+ the index of the last point instead of relying on the dimension
+ of the points array as obtained with GetN(). This increases the
+ accuracy of extrapolation (and drawing) resuls since no undefined
+ points are now used anymore.
+01-dec-2006 NvE AliTimestamp::Add() updated to allow specification of large time differences
+ also by giving e.g. only a certain number of seconds instead of explicitly
+ giving the time difference in elapsed days, remaining elapsed seconds etc...
+ This is very convenient by time manipulations based on GPS data.
+ The extension has been realised by just replacing the relevant if()
+ statements by while() loops in determining the remaining fractional counts.
+ Furthermore, some modulo operations have been introduced to prevent
+ integer overflows.
+08-dec-2006 NvE Memberfunctions SetUT introduced in AliTimestamp to provide convenient
+ ways to set a specific UT date/time.
+20-jan-2007 NvE AliMath extended with Nfac(), LnNfac() and LogNfac() facilities.
+08-mar-2007 NvE AliSample extended with Median and Spread calculation for 1D histograms.
+15-mar-2007 NvE AliTimestamp extended with Sidereal Time and Besselian Epoch.
+ Date/time retrieval via epoch specification introduced and UT time made
+ accessible even for cases which fall outside the TTimeStamp range.
+ As such, the UT and GST info will always be provided via the Date()
+ memberfunction.
+16-mar-2007 NvE Uniform data format introduced for printout of AliTimestamp::Date().
+17-mar-2007 NvE AliTimestamp extended to allow local time printout for a specified offset
+ and addition of a time difference specified as (fractional) hours.
+ Also bug fixed in the fractional hour conversion facility.
+20-mar-2007 NvE Support for retrieval of Local Time (LT) and Local Sidereal Time (LST)
+ introduced in AliTimestamp.
+22-mar-2007 NvE Support introduced for setting of timestamp parameters based on Local Time (LT)
+ in AliTimestamp.
+25-mar-2007 NvE AliTimestamp extended with Apparent Sidereal Time.
+27-mar-2007 NvE Test on date/time validity corrected in AliTimestamp::SetMJD to prevent
+ crash in TTimestamp invokation for very future dates.
+ Also more accurate calculation introduced of the change (dpsi) in
+ ecliptic longitude due to nutation in AliTimestamp::GetGAST.
+28-mar-2007 NvE AliTimestamp::Date extended to provide apparent sidereal time via
+ specification of negative "mode" parameter.
+29-mar-2007 NvE New memberfunction Almanac() introduced in AliTimestamp to provide a
+ central place for calculation of astronomical observables.