Make static links use query redirects

Rather than redirect to an old URL, and then display the same thing as
a query, just redirect to the query screen.  While we are at it,
define /r/* to be any valid query, which opens up a lot of potential
for linking to different parts of Gerrit.

Change-Id: I93a43e5bfe2e7c3b766e8ba9a05cc1901a285920
Signed-off-by: Shawn O. Pearce <sop@google.com>