First working edition of the CalChart ghost viewer.
This allows you to view sheets behind the one that you are working on.
Added some comments to make this easier to review.
Copy sheet to clipboard, paste sheet from clipboard
Fixed a bug with dot and text colors. The application was using dot colors
for text colors.
Update cc_preferences_ui.cpp

I had made a change to the preferences to make sure that the colors reset on "Reset All" - I didn't carefully consider this change though, so I don't want to keep it in as a permanent fix to that issue.
Update cc_preferences_ui.cpp

Just making the preferences file identical to the original.
Updates: making ghost_module behavior an enum based parameter.  Removed ghost_source and ghost_tool.  (enforcing my coding style, sorry :)
Updates: making ghost_module behavior an enum based parameter.  Removed ghost_source and ghost_tool.  (enforcing my coding style, sorry :)
Merge branch 'GhostSheetViewing' of https://github.com/calband/calchart into GhostSheetViewing
Some cleanup changes suggested by rmpowell and noahsark
Changed clipboard format name for sheet
changing const data style from macro to static object, making it a specific type.
changing add sheet to go through field-view, which will enable do/undo actions.
made windows build work with changes to ghost module
A "Dot Swap" tool. It just trades the positions of two dots on a
stuntsheet. Useful when moving points around to solve collisions - this
saves some of the time that would normally be used to drag and drop.
Now using an std::unique_ptr
Merge branch 'CopyPasteSheet' of http://github.com/calband/calchart into CopyPasteSheet

Conflicts:
	src/field_frame.cpp
First version of show/hide label.
It does not save label visibility right now, and I don't want it to yet.
It also has screwed up button bitmaps
First working version of Collision Warnings - collisions are labeled in
orange now, when dots are a step apart, and purple when they are actually
on top of one another.
Update cc_preferences_ui.cpp

removing whitespace diff