Clean up when exactly we should save settings, and add in checks to make sure we do not do it incorrectly

This fixes a bunch of bugs with setting the title for widgets, deleting
widgets, etc.  It also reduces the amount of code duplication, which is
always a good thing.

Replace 9 seperate valueChanged() signals with just 1, and remove the resultant tons of code duplication

Change for the new RC calibration widget, still needs an if/else to load the old one for unsupported systems

Fixed setting the slider position based on parameter values for variables that don't have a range specified.

Removed commented-out references to setStyleSheet(). Moving towards all styles being set in .css files

Changes for new calibration in APM 3.0 (Re: https://github.com/diydrones/MissionPlanner/issues/38), and change in some of the serial timeouts