Remove some lines that weren't consistent with the earlier
suggested patches.

Input methods are way too complex for us to map them to the VNC
protocol in any sane manner. Best just to disable them and rely
on simple keyboard behaviour when the viewport is active.

Boiler plate code to intercept system events from FLTK so that
we can generate proper keyboard messages.

Remove the FLTK simple keyboard system and reorganise things in
preparation for a more direct approach.

It makes things more self contained (although you still need to
download FLTK itself), avoids the confusion of STR:s in varying
states, and allows us to refer to patches that aren't available
on an STR.