Fixed a stack overflow bug when using the regression fitting command

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.

Linechart UI improvements

Canceling out of file selection in the logfile plotter no longer triggers a warning.

Added a check for a division by zero in AbstractCalibrator::logAverage()

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.

Fixed canceling the Logging function through the button on the main toolbar

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.

Added text (component id) to cone/circle symbol symbolizing pose data from that component in 3D view.

Unified all object selections in 3D view via right-mouse-click, and added mouse-based terrain translation/rotation.