Concatenation with integers and string now properly supports 64bit types

git-svn-id: http://svn.code.sf.net/p/angelscript/code@1995 404ce1b2-830e-0410-a2e2-b09542c77caf
Script classes can now implement opConv and opImplConv to support type conversions


git-svn-id: http://svn.code.sf.net/p/angelscript/code@1996 404ce1b2-830e-0410-a2e2-b09542c77caf