Add "Flag as Booster" item to fitting menu
Added booster fit toggling in database, menu label toggling, and migration code
Fixed cases where fit.booster column might contain null instead of bool
Added getFitsWithBooster query
GangView is not aware of changes to booster fits
Fixes bug with fit copy.

`copy.deepcopy` was not copying the booster property of the fit for whatever reason - I blame my poor understanding of copy.
Bug fix and more work
Fit choice works and is properly applied. Dragging and setting via context from ship browser does not.
Got rid of `UpdateFleetFitsUI`  and baked it's functionality into `fitSelected`; now supports dragging/setting via right click.
Fixed style issue that caused content to move when switching between choice and static text
Refactoring of code, along with general housekeeping. Also, character menu is now disabled with no fit selected.
Changed "Set Booster Fit" option to a boolean menu item with fancy checkbox.
Added icon to show boosting fits.
Revert "Added icon to show boosting fits."

This reverts commit f7fdcfcd4e354ad98070d0d93f865f40e98fdb12.
Added booster icon

This is technically a button, and acts like a button without a function. Must look into making it a proper icon and not a button.
Help message in fleet window
Fixes incorrect setting of `draggedFitID` when selecting booster from menu
Merge branch 'master' into fleet
Expand fit choice to available space
Merge pull request #53 from blitzmann/fleet

Fleet booster refactoring