Fix compiling errors (and some warnings) for c++ builder. Thanks @Greatwolf for most of the patches and @cfanderek for reminding us again about this stuff.

git-svn-id: https://irrlicht.svn.sourceforge.net/svnroot/irrlicht/branches/releases/1.8@4455 dfc29bdd-3216-0410-991c-e03cc46cb475