Rename swarming -> skia_swarming.
Some required heavy modification to remove other dependencies on modules
in build.git.
Expected changes:
- RECIPE_MODULE[build::<module>] -> RECIPE_MODULE[skia::<module>]
- No more runit; directly run through Python.
Bug: skia:6628
Change-Id: I1b1370ed387966222ce10731771dbde9020cf542
Reviewed-on: https://skia-review.googlesource.com/17448
Commit-Queue: Eric Boren <borenet@google.com>
Reviewed-by: Ravi Mistry <rmistry@google.com>
