Add shortcuts for editor functions and improve local storage backup.

[Undre4m]

Add shortcuts for the editor functions so they can be called through a key combination. E.g.

CTRL+X for executing the current code. CTRL+L for loading saved state.

Useful for faster execution and would help when large pieces of code are introduced on the editor for testing.

Improve the saving of states to the local storage by making them more intuitive or providing a quick sum-up of the availability of this function. A save button for stashing the current state could also be provided.