feat(rxPageTitle): Strip HTML from page title

Closes #660
test(rxPageTitle): attribute and escaped char tests
feat(rxUnsafeRemoveHTML): New filter
docs(rxPageTitle): Update README
feat(rxPage): Enable access to rxPageTitle setTitleUnsafe
Merge pull request #661 from rackerlabs/660_strip_html_from_page_title

feat(rxPageTitle): Method to optionally strip HTML from page title