GUI: Allow user to adjust display font size

As a scientist, I want to be able to adjust the size of font used in the GUI, so that I can view the screen from a distance.

'''Acceptance Criteria'''
1. I can grow/shrink the font size.
1. I can reset the font size to its default value.

'''Notes'''
1. Should the user be able to choose font size on a view-by-view basis?
1. Should the user be able to choose the font as well as the font size?
1. Could just use grow/shrink font buttons (see, for example, MS-Word).
1. Some views use larger/smaller fonts than others (e.g. Dashboard vs Synoptic display). If growing fonts globally, should we maintain the relative size of these fonts?