Use a context manager for the field module
Move graphics and diagnostics functions to seperate modules
Remove unneccessary code

The graphics methods are now in tools/graphics
Use context managers for beginChange/endChange in Scene and Fieldmodule
Use refactored graphics module
Remove references to zincWidget
Add auto reference options
Fix mirror data bug
Add options for rigid fitting
Update names
Use graphics module to create standard glyphs
Experiment with setting the Zinc context
Remove debug prints
Update context creation, add status bar, change reference/fitted view
Implement simple undo stack
Prefer PyQt4 over PySide
Add datapoint diagnsotic snippet
Refactor to use a region parameter instead of the default region
Add functions to to create different order Lagrange meshes
Add function to convert a linear mesh to cubic Lagrange