Add TTF bugfix functions to resolve GitHub issue #50.
When detecting that libpng is not in version 1.5, the script will now
download and compile a new libgraphics.so for dwarf_fortress_unfunck to
remplace the old. It will normally solve all the problems of tilset "not
found" on distribuitons based on arch linux (with libpng in version 1.6)
Soved tab vs space problem
Soved tab vs space problem
Corrected some typos in commentaries
Have still forgotten some spaces
Use new df_unfuck cross-distro buildsystem