Step 2 in 7" support for tablets.

This is a cherry-pick of f872876699a22d90bc39f7efaac5b21e224e7c82 :
- Use new recommended sw600dp instead of w600dp to avoid having the
"personality" change on configuration change
- remove the use of xlarge/large for specializing values since the
framework team discourages any use of the buckets (and have also changed
the ordering so that they take lower priority)

Change-Id: I645bfb7cddcda8b53569af927f6fa23180e73e1f
39 files changed