Add material compare in Drawable2D.
Delay call Drawable2D::GetVertices.
Fix LuaJIT search path which was broken after v2.0.3 update.
Add visibility property in Drawable2D.[ci skip]
Use multi thread check Drawable2D visiblity.
Added Descriptions Mapping for LuaScript Packages' Hooks.

In "ToDoxHook.lua":
- Added "getCurrentDirectory" function (to test on Unix systems);
- Added Process to fetch and map C++ headers' descriptions to Lua elements;
- TODO: Intergrate for Doxygen output.

In "ToZerobraneStudioHook.lua":
- Writes descriptions from Lua elements.
Force line break cleanup to avoid bad behavior on Unix systems.
Merge branch 'master' of https://github.com/silverkorn/Urho3D