Library Header Changes

* Set some good defaults for header order, widths, and show/hide values with
an eye on a really good first-run experience.
* Delete header_state values on upgrade, since we can't use them
across db versions.
Merge branch 'master' into columns-reset-to-default
Make sure to clear out all header states
Make most models inherit the default hidden-column settings.
Make column name / widths easy to set up.
better comment
no need to change old schema update processes
Do the header_state reset in schemamanager.cpp
Add tooltips for UI toggle buttons
LateNight: Use new tooltips, fix some issues
Use double-precision for rectangle calculations in WVuMeter.

Fixes quantization glitches in SVG rendering.
Unify logic for all Paintable::draw methods into one.

* Remove pixmap-rendering for rendering SVG with a source rectangle. I
  added this hack when I was adding SVG support because I didn't have
  time to figure out the problems it caused for VU meters.
* Adds a FIXED and STRETCH_ASPECT DrawMode to Paintable.
Clean up include orders.
Add Paintable::DrawModeToString.
Add SkinContext::selectScaleMode.
Add Paintable::drawCentered (for WKnobComposed, essentially).
Add scalemode support to most widget images.

* Remove WStatusLight SizeMode as DrawMode is more general and covers
  its use cases.
* Only call QWidget::setFixedSize if the DrawMode is FIXED.
* Use FIXED as default DrawMode for most widgets for backwards
  compatibility.
* Switch most Paintable::draw() calls to rectangle targets instead
  of (x,y) points. This allows the DrawMode to do the right behavior
  based on the mode.
Deere: Set slider stretch options.
Merge branch 'columns-reset-to-default' into headerstate
Add custom library header save/restore code.

Should migrate current 1.12 installations from the old QT binary blog
to the new protobuf format.  This won't help us for users upgrading
from 1.11, but all future upgrades should be much smoother.
Includes a small roundtrip test.
nicer debug log
Merge branch 'columns-reset-to-default' into headerstate