Move development guidelines into docs
Move taskoverview into docs/
Split up development page
Refactor tasklist for easier integration by taskoverview
Increase test output delay to avoid bogus test fails
Fix links
Don't use markdown in changelog
Update syntax check command
Split GCE manifest into regular & backports

Some people want the security team-supported 3.2 kernel, while others
want the better performance of the backports kernel. Both flavors are
currently provided in the Google Compute Engine debian-cloud project.

Also add OpenSSH to the backports flavor, for parity with the current
GCE backports image based on build-debian-cloud. This backport is
included for performance reasons, in line with the purpose of that image
flavor, and as discussed on the debian-cloud list.