Google App Engine SDKs 1.9.4

Upgrades App Engine SDKs to 1.9.4 across Java, Python, Go 32/64.
SHAs verified from Google's download site at https://developers.google.com/appengine/downloads

Closes #28943.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
geogit 0.8.0

Upgrading Geogit to 0.8.0

Closes #28941.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>