Set Prec to highest for Tab/Esc key Commands and export Commands

[s-cork]

Currently the tab key for the abbreviationTracker has no precedence, but this should probably be set to highest given that the tab key might also be assigned to indentation.

Also please export the key commands, that way I can assign tabKeyHandler to Enter.

[shshaw]

You can manually up the precedence for Tab by wrapping it in Prec.high