Debug error appeared on windows when buttons are enabled at the end of
the calibration and focus.

By emitting a signal instead of calling the function to enable the
buttons directly, windows stops complaining about threads interacting
with the GUI.

Documentation has been added for the less obvious public and private methods.
Some of the methods in the model should be shown as private, so have
had methods refactored.

Test file names need to be distinct, as CMake does not
 allow for build properly when file names are the
 same.  Also adds main methods to test classes.

Creating a new focus now saves a nexus file to the file system. The old GUI saves multiple file types, but since I'm not sure what they actually use, nexus seems like a safe proof of concept for now.

Creating a new focus now saves a nexus file to the file system. The old GUI saves multiple file types, but since I'm not sure what they actually use, nexus seems like a safe proof of concept for now.

The calibration tab is now able to notify any tabs that subscribe to it what the current calibration is.
For now, this allows the focusing tab to perform it's algorithm based on the most recently loaded calibration.

Tests added for plotting functionality in the model and the current functionality of the presenter.

Initially the plot buttons and parameters didn't do anything in the model. Checking the box now sets if plots are created for the workspaces.

Initial version of the model. Currently missing the plotting, file creation, and file system interaction.