Improve styleability of RecentChanges form

The current form is a sequence of text and links without
any structure which makes it impossible to apply styles.

This patch wraps some elements in spans and assigns class
names, so that they can be targeted by CSS rules.

Change-Id: If3ca99b0bd251528ced856822c8e52a18657deb8
Merge "Improve styleability of RecentChanges form"