Update Settings::percent funciton.

Updated it so that it now handles fractional percentages. The
frac argument now tells whether or not the setting accepts fractional
percentages.
Fix parseRegion() to call Settings::set() instead of get().

This was resulting in us not setting a value for Y values of region
anchor settings at all.
Turn tests with decimal percentages back on.

Had to make a few changes to regions.json and viewportanchor.json
as well do to bad JSON data.