Merged from 1.8 branch, revisions 4345-4378. All release fixes since the branch to 1.8, and some fixes after that. Now commencing development on this branch, and only bug fixes on the others.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4379 dfc29bdd-3216-0410-991c-e03cc46cb475