PLAY: suppress sort_name_list incompatible pointer type warning.
PLAY: show "/" for the root directory button in the file menu on unix.
PLAY: truncate dialog text when strings are too long.
PLAY: retain case in file path prompts.
PLAY: retain case of filenames in batch scripts.
PLAY: default to lowercase suffixes.
Merge pull request #9 from wangds/play_sdl

PLAY: SDL port. Applause
QUICKFLI: fix crash due bad refactoring.

Faulty commit in 91ddac838d8ea6a64b7f212f2db7423b012322db.
Fix a bug with the indices in cset_colors.
Use memmove for copy_bytes/copy_words as src/dst may overlap.
PLAY: clip source dimensions when saving the buffer under the mouse.