Merge revision 4920:4921 from trunk to ogl-es:
- Added sphere frustum culling support.


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code@4935 dfc29bdd-3216-0410-991c-e03cc46cb475
Merge revision 4922:4923 from trunk to ogl-es:
- Added helper functions for converting between wchar and utf-8.


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code@4936 dfc29bdd-3216-0410-991c-e03cc46cb475
Merge revision 4924:4925 from trunk to ogl-es:
- Fix bug with multiple SetPixelFormat calls.
- Fixed bug related to memory release in PNG image loader. Thanks elephoenix for it.
- Fix crash in CGUIListBox when users pressed end key folled by any other key in an empty, focused list box (thanks at porcus for report and patch).
- Fix use of enabling defines for wal2 (halflife) image loader. Thanks to hendu for noticing.
- Fix proper screenshot creation in test by inserting the stabilizeScreenBackground call.


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code@4937 dfc29bdd-3216-0410-991c-e03cc46cb475
Merge revision 4926:4931 from trunk to ogl-es:
- EditBox works now with numpad on X11
- Remove unnecessary cast


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code@4938 dfc29bdd-3216-0410-991c-e03cc46cb475
Merge revision 4932:4938 from trunk to ogl-es (4932 ignored as it was the revert of an earlier patch which wasn't merged). We've now catched up to current trunk again.
- Fixed issue with functions for convert from/to UTF8 and shared libs.


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code@4939 dfc29bdd-3216-0410-991c-e03cc46cb475