Add basic functionality for tilt scheme selection

Changes in detail:

* Add `--tilt-scheme' option
* Remove use_gamma_flag and make `--gamma' option required
* Remove exception handling from ..._assign_from_args function
Rename ai_single_axis to approx_inverse due to added functionality
Remove use_gamma_flag
Go back to list of static lib files

Apparently, dependency resolution works better compared to the
'-l<lib>' variant
Give credit to authors of 3rd party stuff
Enable option for tilt scheme selection
update TODO
update version in configure.ac
rename misleading pointer parameters of gfunc3_init_mrc
remove trailing whitespaces in Makefile.am
minor changes in approx_inverse.c
compute program name only once in convec_comb.c