map_orphan_and_risk - next try for upload method

should work around nvidia600 driver issue which will flush gpu on syncing
also increase buffer size by orphaning
remove ati workaroung for mipmap creation

isn't needed any more by merging mapmap_fixes
Revert "map_orphan_and_risk - next try for upload method"

This reverts commit 17747fcfb8a4f076ea97d8d5781539735ab32f72.

On orphaning, some gl drivers do heurisitics where to store the buffer.
As the hack may only work on pinned memory, it would be much less deteministic.
fix texture parameters
revert b5fe39b8c721 "fix texture parameters"

these parameters are really floats. I was just wrong
Implement OGL sampler cache. Allows binding a texture multiple times with different parameters. Also possibly gives a very small speed improvement.
Check for sampler object support, just to be nice.
Remove some unneeded sampler-related calls in BPStructs.
Minor sampler cache cleanup.