fix libbsd header file search location 

with the deformed stars of calculate_rotation_variables

added option to common envelope evolution to set the rotation
rate of a merged star to the keplerian breakup velocity
(again, as in calculate_rotation_variables)

added macros to control extra logging (tidal lock, rotation rates)

updated show_derivatives to be say when all the derivatives are zero

tried to smooth the prevent_overspin function without
too much success.

add logging for tidally locked and medium rotator systems

fix bug where angular momentum from decretion discs was not being removed from the system. such angular momentum now follows the standard gamma prescription

changed F to |F| in discs ... let's see if it works :)

also for latest string copy updates

add va_end to places where Map_GSL_params is called : this is (formally) required although was usually forgotten.

(note: probably using glibc it doesn't matter, it might on other platforms)

a way to change the step size in the GSL solver

fix to allow build when libbsd is not available

fixed some minor code warnings

but should have been looking in GSL's bin directory

changed strncpy to strlcpy, and defined BAN_UNSAFE_FUNCTIONS which, in binary_c_code_options.h, stops various functions which are likely to cause buffer overruns from being used (e.g. strcpy, strcat, gets). This requires strlcpy instead of strncpy, hence libbsd.

Use pkg-config to get the library and C-compiler flags required for the Makefile. 

fix the Makefile to use the same LIBS as libbinary_c.so's makefile

instead of changing max_evolution_time, we now limit yields_dt instead