Preserve links in commit and change messages

We are expecting plain text links in the commit message and any change
 messages/reviews so we can use the textview's property 'autoLink' to
 pretend that this contains link-enabled text.
An internet intent will fire, which will automatically open the link in
 the user's browser.
If we added intent filters for gerrit urls, we could intercept these
 intents.

Change-Id: Iff64d83b9cabcec3fe1a492c52ce0cb2eb55dbe1