Refactor trivial equality check.

Summary: Makes it easier to add new pattern match cases.

Reviewed By: @jwatzman

Differential Revision: D1611174
Remove and '--all' and '-- [rest]' option to hh_server

Summary: They are unused.

Reviewed By: @jwatzman

Differential Revision: D1610702
Hoist out init code from ServerConvert

Summary: I am trying to isolate all the init code in one place, so that saving /
restoring state will be easy.

Reviewed By: @jwatzman

Differential Revision: D1610705
Clean up MainInit.go.

Summary: It seems like there's no need to run ServerPeriodical.init when
we are doing the one-shot hh_server --check. If so, we can easily factor
the four statements into one if-then block.

I will be refactoring the init process in subsequent commits in preparing for
the save / restore state feature, and this change helps that refactor.

Reviewed By: @jwatzman

Differential Revision: D1610704
Remove hh_server --suggest

Summary: It seems to have been replaced by the client-side suggest
interface.

Reviewed By: @jwatzman

Differential Revision: D1610703
Separate --check code from init code.

Summary: Should make it easier to see if we're saving / restoring global
state correctly.

Reviewed By: @jwatzman

Differential Revision: D1610792