Update makefile to include help documentation for wipe, and to sanity check
environmental variables.
Added "package" to Makefile help.
Fixed parameter strings in Makefile sanity check.
Move sanity check to individual files.
Fixed Makefile sanity checking to work for all command line argument
variants.
GCS: Add board plugin for taulabs

Currently this plugin supports Freedom and Sparky.  This is required
for calibration to apply to the mags for them.
GCS: Update copyright line to reflect TauLabs instead of PhoenixPilot

Some files never were updated.
GCS Board Plugins: Removed TODO that meant nothing
GCS Control: Make SDL optional

To compile with SDL joystick input support compile GCS with
make GCS_QMAKE_OPTS="CONFIG+=SDL" -j7 gcs
GCS Control: Remove commented code
Fix for excluding SDL
GCS Controller: Add an option to control via GCS Receiver instead
GCS Control: Update the GCS Receiver object
GCS: Also exclude sdlgamepad library when unused
SDL: Mask out more includes
SDL: Only copy the dll when used
Path to turn on compiling SDL by default.

Turn off SDL with: make GCS_QMAKE_OPTS="GCS_NO_SDL=NO" gcs
Remove test variable.
Uploader: Use board plugin for getting the board name

Previously these were redundantly coded.
Uploader: Use board_plugin for image of boards