Fix postgresql upgrade script wrt sequences

The upgrade script tried to re-create the sequences even if it was already
existing. It turns out that the name `foo;` was compared to `foo` because the
query is actually `CREATE SEQUENCE foo;`. Adjust the regex to ignore the `;`.
Merge pull request #43 from Lekensteyn/fix-psql-upgrade

Fix dbdelta's matching of sequences which require updating for Postgres installs.
Stop using spaces in the DSN for Postgres.

Semicolons are supported, I have no idea why we never used them.
Vastly improve DSN parsing in the installer.
Fix DSN parsing for database upgrades. Again, mainly for Postgres.