[opwig-lua] Deeper namespaces correctly wrapped.
[opwig-lua] Starting direct import of inner modules.
[opwig-lua] Wrapper exports submodules too.
[opwig-lua] Wrapper exports submodules directly.
[opwig-lua] Properly close generated namespace.
[opwig-lua] Refactored repeated generated code.
[opwig-lua] A few tweaks...

- Changed module export code order.
- Fixed an old issue with script loader.
[opwig-lua] Empty universal getter for module variables.
[opwig-lua] Universal getter base code.
[opwig-lua] Separating some code generation in different files.
[opwig-lua] Separeted wrap types in wraps.h
[opwig-lua] Isolated wrap list code generation
[opwig-lua] Generating empty unused getters
[opwig-lua] Registers module's getters.
[opwig-lua] Wraps getters for variables.
[opwig-lua] Refactoring generated code:

- WrapName() -> GetWrapName()
- Stack optimizations at OPWIG_Lua_UniversalGetter()
[opwig-lua] Code spacing issues
[opwig-lua] Refactored wrapper's module init code:

- Isolated metatable preparation code in another generated function.
[opwig-lua] Setters in the modules' metatables.
[opwig-lua] Setters check for existence of variable.