Fixed a number of bad bugs in the HUD, will need a bit more write / SVG rewrite to make it pretty, but is substantially more accurate and reliable now

Addressed issue #26. Select System, Plugins and System are disabled when neccessary. Removed style-outdoor-dark.css. Moved the other two .css files and Vera.ttf into files/styles.

Erros casused by all of the mergedd branches are now fixed for qgroundcontrol.pro. Working on fixing the errors that now appeare in qgcunittest.pro.

Put libraries into one libs directory under qgroundcontrol. Changed the neccessary files with references to those libraries.

qgcunittest.pro now compiles and runs as long as run in terminal in projcts->Run Settings is unchecked.

Fixed a couple of uninitialized arrays within the MAVLinkDecoder. It would result in weird time values in some data logging instances.

Replaced the autopilot-specific inclusion of MAVLink to be more generic. Now if you have no actual QGC modifications to make and just want your messages to be available for viewing/logging you can just create the user_config.pri file and override MAVLINK_CONF.

Also changed calculateRegression(...) to return a bool, as that's all it needs.

Fixed a stack overflow bug when using the regression fitting command in logfile plot. Solution involved just allocating on the heap instead of the stack.

Added a check for a division by zero in AbstractCalibrator::logAverage(). This was causing a crash when attempting a calibration when there's no RC data being received.

Modified the Linechart widget so that the "Show units" button is under the "Curve Selection" frame, which is what it actually modifies.
Also moved all of the UI that was under the "Curve Selection" to inside of it at the bottom so that the grouping of UI elements is more coherent.