3.6.4 Release

[Paul Ramsey]

While we do not have a lot of changes since the last release, we do have an important fix to upgrading which resolves (mitigates) a long-time issue with SRID lookup during upgrade, as well as a security patch which I would like to put to bed.  Since there will be a lot of PostGIS packages cut over the summer I would like those packages to have these changes.

+1 (numbers are cheap)

P