This allows you to add XY graph plots of any data.  For example,
x,y position data of a servo.

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.

- DLL copying belongs in qgroundcontrol.pro, not qupdate.pro
- Turn on link time code generation for better (global) optimization

Instantiate a PX4 config view in PX4 mode from start, since boards with just the bootloader (or no working telemetry) cannot be flashed else.

This reverts commit 09452414.