Fix: MPC200 driver chokes on junk serial data when ROE stop button is
pressed
Beginning overhaul of scan programs
Filled in some missing code
Fixed component imports
Continued reorganization
Merge branch 'develop' into scan_programs
Fixes; rect and line scans appear to be running as before the reorganization.
Scanner / task GUI / rect control now updates its duration and exposire times correctly based on sample rate and downsampling
corrections; appears to be working.
Some minor tweaks still needed.
Make duration <=> pixelSize both user editable
- Draw rectangle showing overscan region for rect scan
- Add Parameter 'title' option to separate internal parameter name from
  displayed name
Merge branch 'scanner_fixes' into scan_programs

Conflicts:
	acq4/devices/Scanner/TaskGui.py
Corrections following merge from scanner_fixes branch
Added notes on rect scan classes needed
progress on new solver for rect scaning
Further work on a complete solution for solving rect scan systems
Added some more tests, fixed a couple of bugs
added save/restore test; fixed bugs
minor changes to rect scan / state solver
Hide default button in parametertree for read-only parameters