Squashed 'Extern/LuaBridge/' changes from 4b1d359..74101d4

74101d4 fix puzzling errors in addProperty: previously, for example, a property of
a7e3271 RefCountedObject.h calls assert(); therefore it should #include <cassert> as LuaBridge.h does
494900a Static assert for illegal construction, fix manual
fb95089 Fix bug with reporting getClass() error and Lua stack
c847fd0 Iterator support
80bd834 Add Iterator.h
6007412 Add raw table accessors to LuaRef and Proxy
aa61b31 Remove unused LuaBridgeExtras.h
26cc61a update manual
80429b5 Add version contants (Closes #38)
2f6ca02 Add typedef for RefCountedObject
7f4e5dd Make RefCountedXXX extensions compile stand-alone
d53fd60 Update Manual and README
261c0a5 Update manual
ad7a4f9 Update Manual and README

git-subtree-dir: Extern/LuaBridge
git-subtree-split: 74101d4f84143a96b63a86c0f747b62911cd42da
Merge commit '0a04212091d4e17e83d4a827f9ebb110f7727a9c' into develop