added / updated / corrected COPYING information in the core, aac, alac, adplug; renamed optmath.h to fastftoi.h
added COPYING to alsa, ao, artwork
added/updated COPYING in cdda, converter, coreaudio, dca, dsp_libsrc, dumb
added COPYING to ffap, ffmpeg, flac, gme, gtkui, hotkeys; changed gme plugin source license to ZLIB
fixed bug #1050: crash when loading playlist from cmdline