[Ohrrpgce] SVN: teeemcee/10723 Fix a number of crashes/errors when sprite slices can't be loaded or due

[subversion at HamsterRepublic.com]

teeemcee
2018-09-29 17:58:24 -0700 (Sat, 29 Sep 2018)
273
Fix a number of crashes/errors when sprite slices can't be loaded or due to 8/32-bit issues

Also, automatically disable sprite settings flip vert/horiz,
transparent, and dissolve if they are supported (for 32-bit sprites) -
this also helps to prevent null ptr dereferences
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U   wip/allmodex.bas
U   wip/slices.bas