Update .hhi files for ConstSet, Set, and ImmSet

Summary: This diff updates the .hhi files to reflect the changes from D1435557.
There was also a bug introduced by D1435557 which removed "Container" from
the list of interfaces implemented by ConstSet; this diff fixes this bug
by adding "Container" back to ConstSet's list.

Reviewed By: @elgenie

Differential Revision: D1551381
typechecker: match return types, even with php parent

Summary: Facebook: enabled by www conversion efforts over the past few months

Reviewed By: @jwatzman

Differential Revision: D1542002
don't emit warnings when we can't bind

Summary: I fixed it so they can actally bind, but it shouldn't emit when it does succeed

Reviewed By: @JoelMarcey

Differential Revision: D1551415