Merge branch 'development' into assets
Add abstract class Asset to represent game's assets.
Add funtionality in ResourceManager to handle asset loading and retrieving.
Add abstract class to represent any renderizable asset.
Add source files from Engine/Assets to compilation.
Minor changes in Asset class behaviour.
Fix wrong placement for `const` in Render method of RenderizableAsset.
Move implementation of GetAsset method to header.

This is due to restrictions on the compiler where a non-specialized template function must be on the header.
Add Sprite asset class.
Asset class now is abstract with ToString method.
Implement ToString method in Sprite class.
Fix bug where ResourceManager where adding an extra '/' to GetPath
Correct typo in documentation of method.
Change TestScene behaviour to make it simpler.
Fix wrong custom scene creation in TestGame.
Add support for SublimeClang and SublimeGDB in Sublime's project.
Included .hpp files to SOURCE vars in CMakeLists.txt

This fix an issue with Qt Creator IDE where .hpp files without a .cpp companion won't show up in the project tree.
Create Sprite folder in Assets and added to CMake copy stage.
Add multi-frame animations to Sprite class.
Fix bug because of missing file closing.