Tweak the fixed table header some more.

I make the row header background and font color
transparent.
added a PFButton Class.

This controls the look and feel of all buttons in the
application. Currently the MetricViewController is the only
client using this PFButton class.
Fix the redBanner on the UnitTableViewController.
Reorder the Hardness Chart Keys.

This order is purely business logic, so I had
to hard code the order and pass it to the various
ViewControllers for display purposes.
Added Done buttons to the right of the pickers.

As requested, put a done button so a user can click
when they selected the value you wanted.
Set the fontSize depending on the device.

Also this fixed a compiler error introduced
in commit: 200dfca.