Fix undefined symbol: clock_gettime() on loading
Fix undefined symbol: clock_gettime() on loading

Latest GCCs tend to be strict about the order of libraries at command
line (unlike e.g. GCC 3.4). Now I have to use target_link_libraries()
instead of LINK_FLAGS property to pace -lrt at the end of GCC command
that links stuff.

Zeex/sampgdk,WopsS/sampgdk,Zeex/sampgdk,Zeex/sampgdk,WopsS/sampgdk,WopsS/sampgdk