Introduce standardized exit codes.

Defined a couple of standard exit codes in debugging.hh:

EXIT_SUCCESS 0
-> Use for successful termination of your program.

EXIT_FAIL_CONFIG 128
-> Use if there is a problem with the user's command line arguments

EXIT_FAIL_FILEMANAGER 129
-> Use if there is a problem related to the filemanager

EXIT_FAIL_IO_READ 130
-> Use if there is a problem opening or reading from an inputfile

EXIT_FAIL_IO_WRITE 131
-> Use if there is a problem opening or writing to an ouputfile

1..127 are left for user defined exit codes! If you can think of further
common problems which should be unified, feel free to introduce them
after "131".

I adapated all programs to match these conventions. Please check my
modifications if you rely on exit codes (maybe for important for
acroot_check?)

For MPI parallelized analysis jobs there is a possibility that some
processes do not get any events or files to process at all, this happens
if you use a larger number of processes for small file lists. In those
cases we actually want to return EXIT_SUCCESS from these processes,
because otherwise mpirun will report an error where there was none.
Changed pre-defined exit code values.

Old numbers were conflicting with predefined values from the
system. Thanks Jens!

New scheme:

User defined: 1..63

EXIT_SUCCESS 0
EXIT_FAIL_CONFIG 64
EXIT_FAIL_FILEMANAGER 65 // unless run with mpirun
EXIT_FAIL_IO_READ 66
EXIT_FAIL_IO_WRITE 67
Merge remote-tracking branch 'origin/standardExitCodes' into dev

Signed-off-by: Henning Gast <henning@physik.rwth-aachen.de>
Fix compilation on certain platforms.
Optimize OverlapsWith function.

Following a suggestion by Bastian, store the sizes of the two vectors
involved instead of calling the size() function over and over again.
Juropa: Fix name of MPI environment variable for rank.
MPI: Safety check. Should not modify program behavior.

That part of the code should anyway only be reachable from readers.
Fix tracker position and angle accessors in AnalysisParticle for < 5.9.0

TrackFitCoordinates() object does not exist in files < 5.9.0. Use the
accessors of the individual track fit there.
5.8.0 compatibility: Fix use of TrackerTrackCoordinates in other places.
Documentation: Mark some AC::TrackerTrackFit acessors as obsolete
Clarify units for AnalysisParticle::Tracker\(Phi\|Theta).

Actually there are now two separate accessors. Use
AnalysisParticle::Tracker\(Phi\|Theta\)In\(Degrees\|Radians\)

Also updated documentation.
Documentation: Use doxygen keyword \attention.