Fetch information in bulk about projects.

Reduce the number of datastore api calls at startup when the meta data
about all projects is gathered. Three calls are reduced to one for
each project.

Change-Id: Ia257515e5c4e7d62c662c49f24ba68055c4e55fd
Provide a specific error message when rpc is incompatible

Change-Id: Id9f5ae4ef8f1d2fe0b69f3051cfa418f778abf7e
Increase the reliability of starting the Emulator

Increase the “ubergiveup” threshold to 8. Add the option for the user
to tell App Inventor to keep trying even after the ubergiveup
interval. Add an extra intent to start the Companion if it hasn’t
shown a response yet. This should increase the chances of the
Companion starting on very slow computers. Changed some timers
as well.

Minor change to the build environment so that versions are marked
“dirty” (in the Help->About Menu) if the system was built from a work
tree that has changes that are not yet committed in any branch.

Change-Id: I7bd42d36b3b005c2e072aad60b65afe555e8f2e1