Major changes in the AliL3Transform class. The class has been made completely

Major changes in the AliL3Transform class. The class has been made completely
static, which means that no objects needs to be created anymore. This has also
made impact all classes which use this class (this is more or less all of them),
so that no private AliL3Transform* is needed anymore etc. I think I have managed
to implement the changes everywhere, at least it compiles successfully and exa/test.C
runs smoothly. The only rather important thing one has to remember is to initialize
the correct detector parameters by calling AliL3Transform::Init(path). If not,
default parameters will be used (currently corresponding to AliROOT version 3.06).