title: Searching Gerrit by Commit Message
body: <p>Our team uses a standard of prefixing all commit messages with "bz12345:" (where 12345 is replaced by the bug you're working on) and I'd like to be able to search for all commits that have that bug number.</p>
  
  <p>I've read <a href="http://gerrit.googlecode.com/svn/documentation/2.1.6/user-search.html" rel="noreferrer">http://gerrit.googlecode.com/svn/documentation/2.1.6/user-search.html</a> over and over and haven't figured out a way to search for commit message titles.  Does anybody have a trick for searching the first line of a commit message for arbitrary text?  None of message:, tr:, and bug: work.</p>