Das 297 - Implement Undo/Redo

[wardsimon]

Currently the following are a part of undo/redo:

• Add/Remove phase
  • Modifying all parameters
  • Changing calculation engine
  • Changing minimizer and minimizer method
  • Loading/Removing of experimental data
  • Modifying the phase cif (as a string)

The following will not be implemented:

• Changing graphical engines
• Changing Languages
• Changing tool tips

[wardsimon]

Re-opened for review

[arm61]

Some unexpected results when testing:

• In sample pane, when a structural phase is deleted (by pressing the (-) button), clicking undo does not being the phase back
• No plots appear in the experiment or analysis panes (not sure if this is expected)
• When the object being undone is on a different pane to the currently selected, it would be useful to move automatically to that pane