1.13.3, 1.14 series and 1.15.0

[David Cheney]

Hello

1.13.3 has been released (90% done lp builders have not finsihed so
there are no tools yet, but the release notes and tarball are done)

1.14 series branch has been created, and a 1.14.0 milestone,

Please use this document for branches that need to be backported

https://docs.google.com/a/canonical.com/document/d/1M_ZTAtVfz55U_jvzXaMEIZ2-yqPqjAeIIiQxEW7mfe0/edit

Current trunk focus is 1.15.0