engine:
* sector-like sprite clipping now works with x- xor y-flipped actual sprites
mapster32:
* corruption checker has been hooked up to loading/saving routines to inform/warn the user
* also warn if mouse pointer is over corrupt wall which is shown in pink then: you should not move such a wall!
* faster map loading by deferring polymer_loadboard to 3d mode entrance (also removes some 'glGetTexLevelParameteriv returned GL_FALSE' warnings)
* more logical maphack light handling, the logic is still a bit dodgy though
* some menu and misc. function fixup
* redundancy elimination...
API:
* added consts various for 'char *filename' parameters
* loadboard() now accepts bit 4 for flags (formerly 'fromwhere')
git-svn-id: https://svn.eduke32.com/eduke32@1760 1a8010ca-5511-0410-912e-c29ae57300e0