Irrlicht 1.5.1 Released

- Make sure a missing font does not corrupt the skin.
- Fix getAngle in vector2d as suggested by xray.
  This has only a minor impact on s32 vectors.
- bugfix: CGUIFont::getCharacterFromPos regards now kerning
  (found by Arras)
- Add support for range fog in some OpenGL versions.
- Fix for shadow volume removal, submitted by vitek.
- Avoid using X11 autorepeat to deal with broken X11
  versions.
- Speculars are properly exported into mtl files now,
  instead of corrupting them.
- Binary type loading in attributes fixed.
- bugfix: Use make_lower throughout for spritebank filenames
  (found and patched by Ion Dune)
- STL loader fixed: Right-handedness corrected, normals and
  bboxes are correctly added now.
- bugfix: CUnZipReader::openFile no longer returns true for
  empty files. Corresponding test added.
- Big endian issues in .x loader fixed.
- HSLColor methods repaired.
- copyToScaling fixed.
- Fixed problem with highlighting menus when mouse was
  outside sub-menu area.
- bugfix (2796207): menu acted (wrongly) on left-click down
  instead of left-click up.
- bswap16 fallback macro fixed
- getBaseName fixed to work correct with dots in filenames.
- static method isDriverSupported allows for simple
  check of available drivers.
- Some defines added to check for the Irrlicht version of
  the library.
- Make sure all renderstates are properly initialized
- Wrong size for main depth buffer fixed.
- Fix 3ds shininess to the allowed range.
- Fix loading of Collada files from irrEdit 1.2
- Remove texture pointers after texture clear.
- WindowsCE pathnames fixed.
- Some virtuals are now overridden as expected.
- Incomplete FBOs are properly signalled now
- Update to libpng 1.2.35, fixed issues on 64bit machines
  with system's libpng.
- Fixed wrong grab/drop in setOverrideFont
- Added draw2dRectOutline
- rectf and recti added.
- Fix ALPHA_CHANNEL_REF to a fixed check for alpha==127 as
  expected.
- Fixed OSX device bug where screen size was not set in
  fullscreen mode.
- cursor setVisible changed to be called less often.
- OpenGL version calculation fixed.
- OSX device now supports shift and ctrl keys.
- Fixed ambient light issues in burningsvideo.
- device reset for d3d fixed when using VBOs.
- Fix dimension2d +=
- MD2 mesh loader: Now uses much less memory,
  reduced number of allocations when loading meshes.
- OpenGL render state (texture wrongly cached) fixed.
- Fixed animator removal.
- Changed collision checks for children of invisible
  elements to also be ignored (as they're actually
  invisible due to inheritance).
- Fix terrain to use 32bit only when necessary, make
  terrain use hw buffers. Heightmap loading and height
  calculation fixed. Visibility and LOD calculations updated.
- Some mem leaks fixed
- FPS camera resets the cursor better