Implement glBindImageTexture and glDispatchCompute
Remove D3D11_MAP_FLAG_DO_NOT_WAIT Map() flag on replay

* If we serialised out the Map, then it succeeded during capture, so need
  to make sure we wait and do it on replay regardless.
Remove assert that's pointless and has false positives.

* Technically CopySubresourceRegion should only be called for matching
  types, but the handling won't change (we'll just mark dest resource as
  dirty), so this fires when programs are being a bit naughty for no use.
Fix the wrong define being used meaning histogram/minmax were wrong

* Several places were using HGRAM_PIXELS_PER_TILE*HGRAM_PIXELS_PER_TILE
  instead of HGRAM_PIXELS_PER_TILE*HGRAM_TILES_PER_BLOCK and calculating
  blocks as too large. This meant histogram/minmax would miscalculate the
  number of blocks needed and fail to read properly from > 2048 textures
Fix range becoming 0 if both min and max were negative