fixed unix:INSTALLS+= bin, fixed make uninstall

removed bin/release/DwarfFortress redundance (installed my target)
added bin_mod to make dwarffortress executable by default
split share so make uninstall can remove all files (folder /usr/share/etc/memory_layouts still remains)
changed doc so make uninstall can remove files (generation of debian docs is handled by debian/
Merge pull request #62 from Cerbsen/patch-3

fixed unix:INSTALLS+= bin, fixed make uninstall