Bugfix: must not print non-existing model files
Print which SARAH`Start[] command is executed

This helps in case the specified model does not exist and we need
to find out which arguments were passed to Start[].
Merge branch 'bugfix-non-existing-model-files' into development
update ChangeLog
remove files generated by ./configure in `distclean' target
prevent make from failing in case some files cannot be deleted
renaming MSSM test input file for consistency
ignore SARAH output files
ignore test output spectrum files
renaming benchmark test input and output files for consistency
irgnorin generated lattice source files
Refactor timestamp checking routines
Save vertices to file for reuse
Update ChangeLog
add @todo item: generalize definition of Weinberg angle
removing unused SLHA test input file
rename test SLHA input file for conistency
rename generic SLHA input file for consistency
rename MSSM SLHA output test file for consistency
Bugfix: do not hard-code running Weinberg angle

For the calculation of the (tree-level) DR-bar masses we need the
running DR-bar Weinberg angle, expressed in terms of the fundamental
model parameters (gauge couplings, vevs, ...).  This commit uses
SARAH's expressions for the Weinberg angle (ThetaW), Mass[VWm] and
Mass[VZ] to express ThetaW in terms of these fundamental parameters.