Worked on GUI part of adding option to Pref window
Add 'link' between pref window and file for presnt

Sets present.bgcolor on clicking OK, sets color in Preferences window from
Preferences.txt on opening the window.
Changes as to how the user selects Present bckgrnd

Clicking on the color preview brings up a color selector; Inputting a hex color automatically previews it
Shed a lot of weight, some UI changes

Rm CustomColorChooser, add Cancel to ColorChooser,
Formatting changes,
Removed unnecessary listener,
Inerchange preview color and text field.
Done adding Present bckgrnd color to Prefs window

Cursor to hand on mouseover & new border for color preview
Merge pull request #2568 from joelmoniz/presentBckColor

Added Present's background color as an option to the Preferences window.