[BUGFIX] Subcontroller calling, arguments and extension scope

Fixes: #110
[TASK] Switch from catching extension to checking for NULL

This adds a small speed boost by preventing initialisation of the Exception handling sub logic in PHP.
[TASK] Early render-and-return on no custom controller instance
Merge pull request #118 from NamelessCoder/controllerextensionname

[BUGFIX] Subcontroller calling, arguments and extension scope