use the external oae-rest module
Specify base directory, use gitVersion utility
Embeddable link test now uses mocked HTTP server

The unit test for checking whether a page is embeddable in OAE now uses
a mocked HTTP server rather than apereo.org, to avoid any intermittent
test failures due to network connections, changes on their end, ..
Removed activity migration for 3.0.0 to 4.0.0
Merge pull request #838 from simong/838-embeddable-test

Intermittent test failure: previews embeddable check
Merge pull request #794 from simong/794-remove-activity-migration-code

Remove migration block in ActivityDAO
Merge pull request #821 from stuartf/external-restlib

use the external oae-rest module