Homestyx hydra

R1:219ae8b6c950

Remove old "Landing Strategy" code

Summary:
Fixes T12869. This is a very old, pre-Drydock chunk of code from D7486 and some followups.

It does three things:

- "Land to Hosted Git": Obsoleted by Drydock, has been commented out in HEAD for a very long time with no complaints. Disabled by D8719 in 2014.
- "Land to Hosted Mercurial": Could be obsoleted by Drydock with a fairly small amount of work, but currently has no replacement. Unclear if this sees any real use. Not actually disabled at HEAD.
Repository: R1 hydra
Commit Date: Jun 23 2017