ENH: Implement pop-out plot windows.

[bradyzp]

Enable users to plot a selected flight in a separate window (pop-out from main UI) for comparison against current flights.
ToDo:

• Add pop-out window Qt Form
• Modularize plot code from main window to be used in pop-out
• Ensure changes (if enabled) propagate through application.

[bradyzp]

May modify these requirements given PR #51
Plan on implementing a method to pop-out entire Tabs into a new window in future.