* Build the app with -tags="shareware" to compile the free/shareware
build of the game.
* `make build-free` compiles both binaries to the bin/ folder in
shareware mode.
* The constant balance.FreeVersion is true in the shareware build and
all functionality related to the Doodad Editor UI mode is disabled
in this build mode.
* Scenes can insert custom key/value labels to the debug overlay and
track string variables in real time
* Added ability to unthrottle FPS in main loop
Noah