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
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
need the proto file
Fix migrating from the old blob
Make the internal representation of the header state the proto itself
add todo, move model() call out of loop
wrapping
Use the untranslated column name as a key in the state-saving proto
Merge branch 'master' into headerstate
Merge branch 'master' into headerstate
Change columncache object to a map instead of an array
Merge pull request #427 from ywwg/headerstate

Add custom library header save/restore code.