Add xxx_installer::upgrade($version) method so that upgrade stanzas
are separate from install stanzas. In the old code, to do an upgrade
meant that you had to re-evolve everything from the initial install
because we'd step through each version's changes. But what we really
want is for the initial install to start off in the perfect initial
state, and the upgrades to do the work behind the scenes. So now the
install() function gets things set up properly the first time, and the
upgrade() function does any work to catch you up to the latest code.
See gallery_installer.php for a good example.
only implementing schema version 1. This caused install.sql to be
populated from version 1 which meant that after install you'd have to
run the upgrader. No harm done, and the pattern is fixed for the
future.
Alphabetize the tables so it's easier to find stuff.
