Adding hotkeys for authoring Touch UI. Fixes #248.

Added support for hotkeys in touch ui. 

ctrl+shift+e for edit layer
ctrl+shift+p for preview layer
ctrl+shift+a for annotate layer
ctrl+shift+d for developer layer
ctrl+shift+t for targeting layer
ctrl+shift+s to toggle sidepanel
I debated having this always on myself, but left it in since it technically "adds" functionality rather than "modifies" out of the box functionality. Fine with changing if needed.