Schedule repository updates from `arc commit`, not just `arc land`

Summary: Ref T5926. We only pass Phabricator an update hint from `arc land`, not from `arc commit`.

Test Plan:
  - Ran `arc land` and `arc commit` with `--trace`, saw hints go over the wire.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T5926

Differential Revision: https://secure.phabricator.com/D10324
Arcanist - potentially fix some Windows badness

Summary: Fixes T5914, maybs.

Test Plan: will ask users in T5914

Reviewers: chad, epriestley

Reviewed By: chad, epriestley

Subscribers: chad, bluehawk, epriestley, Korvin

Maniphest Tasks: T5914

Differential Revision: https://secure.phabricator.com/D10333
Improve "arc land" error message to mention SVN alternatives

Summary: Fixes T3813. This error message isn't very helpful in SVN; be more helpful.

Test Plan: Ran `arc land` in a Subversion repository, got a reasonable error message.

Reviewers: btrahan, asherkin

Reviewed By: asherkin

Subscribers: aran

Maniphest Tasks: T3813

Differential Revision: https://secure.phabricator.com/D7275
Fix `arc browse path:line`

Summary: Ref T5781. This was broken in some earlier changes in T5781.

Test Plan: Ran `arc browse README`, `arc browse README:10`.

Reviewers: chad, btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T5781

Differential Revision: https://secure.phabricator.com/D10346
Allow lines to be specified as comma delimited number ranges for arc browse

Summary: Ref T5971. We lose validation of the line ranges, but I don't think that's a huge issue.

Test Plan: Ran `arc browse README`, `arc browse README:3`, and `arc browse README:3,6-7`

Reviewers: btrahan, epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Maniphest Tasks: T5971

Differential Revision: https://secure.phabricator.com/D10352
Adjust py.test invocation per T5973

Summary: Fixes T5973

Test Plan: how does computer

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T5973

Differential Revision: https://secure.phabricator.com/D10356
Don't run "flake8" via stdin

Summary: flake8 v2.2.3 (released Aug 25) broke this. Just drop the stdin stuff.

Test Plan: User confirmed in IRC that this resolves the issue.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D10358