Upgrade instructions

Upgrade HTML::Widgets::SelectLayers to 0.07 (or later)
Install Authen::Passphrase
Install Net::Domain::TLD
Install Business::US::USPS::WebTools
New packages/modules for RT 3.6.4: libxml-rss-perl libcalendar-simple-perl libgd-graph-perl libuniversal-require-perl libgd-text-perl
make install-perl-modules
As the freeside UNIX user, run freeside-upgrade username, passing the username of an internal Freeside user.
If freeside-upgrade hangs, try stopping Apache, all Freeside processes, and anything else connected to your database, especially on older PostgreSQL versions.
Run bin/freeside-migrate-events to migrate your (deprecated) invoice events to the new billing events. Keep an eye out for anything which does not migrate. Note: if you have problems with this step, fix the migration, restore the database from backup and start again from freeside-upgrade. Do not continue on with the upgrade!
make configure-rt
mv /opt/rt3/etc/RT_SiteConfig.pm /opt/rt3/etc/RT_SiteConfig.pm.OLD; make install-rt
/opt/rt3/sbin/rt-setup-database --action insert --datadir rt/etc/upgrade/3.5.1
make install-docs (or make deploy if you've got everything setup for that in the Makefile)
You may want to check your ACLs under Configuration->Employees->View/Edit employee groups and grant some of the new rights to one or more groups.

Possible gotchas

"RT at a glance" ("Ticketing Main") blank? Click "Edit" on the right, then click the "Reset to default" button.
Perl module errors? Try make clean then make install-perl-modules then make install-docs or make deploy again
Weird DBIx::DBSchema errors with Pg 8.x like SELECT NULL::text AS "TABLE_CAT" ? Solution unknown...

If you're using an early 1.9 snapshot from CVS, you may need to update the a column type in the conf table for freeside-upgrade to complete sucessfully:

PostgreSQL:

 ALTER TABLE conf ALTER COLUMN value TYPE text;

MySQL (?):

 ALTER TABLE conf ALTER COLUMN value TYPE text;

cust_main::retry_realtime optimization?
Use FCKeditor for config popups for textareas.
small_custview borders inside RT look janky
bin/fs-migrate-events doesn't make events that apply to a single agent into agent-editable events... perhaps it should?