[Gingerbread] Partial fixes for 'saved pages' view

* use support library to enable action mode
* use WebView.scrollTo instead of setScrollY (more important for when activity is killed/restarted than saved pages)

Needs next commit to actually load UI.

Change-Id: I6a68e56ea65b82e69a070d7f1d17ab63a7c323fa
Merge "[Gingerbread] Partial fixes for 'saved pages' view"