Switch to a fully git-based regime

 * Clone from private repos
 * Work from the develop branch
 * Use tags for base revisions
 * Generate original tarballs using git archive
 * Generate patches dynamically

Change-Id: I093957ea9b4665ca8492f3d4e6bf6e7cba440827
Allow user to specify reference repos to reduce downloading

Change-Id: Ia9b7dd58517fdd501fcbaeeccad45c59459d33a7
Implement a new build-and-install script

 * Based on previous checkout-and-build-mono script
 * Checkout no longer needed since this is done by initrepo
 * Don't git reset/clean/pull
 * Allow use from a different directory
 * Cosmetic improvements

Change-Id: I071b72611139b24a5df45463bb071f22f8fb2262
Improve trace output of build-and-install

Change-Id: I19498bd79f3d1ff9c0cb33bae573bde1ee3dd387
Implement dirty check and forcing option in build-and-install

Change-Id: Ie4b4c7967cd7d6811cf4124d33f549b5dc1cf400
Update mono changelog

Change-Id: Ic9fa222473013de21d88ed92d2fa16697b101bb9
Support custom debuild options

Change-Id: I6b5f42bbd3c9d106e2d7123876db68b4c3b5bcbf
Ensure make-source-package uses the latest commits

Improve the bare source.git cloning so that remote branches really are
mirrored.

Change-Id: Iab3b9f853e11916988fb13fb31ecfae50642dfe8
(cherry picked from commit 7aaad253902cb78d0e39bdc0a1379cc28d97a1ef)
Allow bare repos to be used for reference in make-source-package

Change-Id: I5dd23513ddca9d631dc97ecf7ab7146271c2820c
(cherry picked from commit 415b7de20cf543450a2f3fe837486d2ce2f3b5cd)
Update libgdiplus changelog for 2.10.8-2

Change-Id: I95b1ca14fc2d1bb3e5a4f06632a76fbfdf285035