Function and Address Following

[direwolf314]

Should jump to the associated address/function on double click/enter and keep a queue of jumps allowing 'Esc' to return to where we were.

Needs to be done:

• 'Location' stack only pushes the current cursor position. This makes hitting 'Esc' wonky. Fix.
• Bind [Enter] to do whatever double clicking would
• Make inline addresses/labels clickable. May require some work down the recursive-descent path...