GXemul Code2

Nicer tab completion in CommandInterpreter, by showing Methods and Variables separately.

State variable names of components can now be tab completed.
"Running" a variable (e.g. cpu0.pc) will print its value.

Adding a (so far dummy) ComponentPalette area to the GTKMM GUI.

Removing obsolete TODO items from TODO.html.

Max 80 columns.

Max 80 columns for MIPS_CPUComponent.cc.

The continue command now clears the Undo stack.

Upgrading the configure script check for gtkmm-2.4 from
version 2.12.5 to 2.12.7, to be in synch with my system.

Action::Execute and Undo are now private, and only reachable
from the ActionStack (now a friend class of Action).

Updating the TODO file.