setter for the default particle mass in L1 track fit; move global functions to L1Fit class
- setter for the default particle mass for L1 track fit;
- global functions for material corrections from L1AddMAterial.h are moved to the new L1Fit class
- particle mass as a member of L1Fit, not as a parameter in function calls.
- remove default parameter values in the material routines in order to prevent bugs
- few bugfixes