Hack Router Versions Save

This release:

• contains several performance improvements (thanks to @azjezz )
• supports current nightly builds of HHVM, and is expected to support 4.136

This release supports HHVM 4.88.0

• list allowed FIXME codes in .hhconfig (required since HHVM 4.62)
• migrate array type annotations to varray or darray (required since HHVM 4.68)

This release:

• supports the latest release of hsl-experimental and hack-http-request-response-interfaces
• permits any KeyedContainer to be returned from BaseRouter::getRoutes()

• added MethodNotAllowedException::getAllowedMethods()
• HEAD requests will no longer be handled by GET controllers if any other methods are defined for the request; this is to avoid issues such as https://blog.teddykatz.com/2019/11/05/github-oauth-bypass.html

No longer depends on the disallow_array_literal setting being turned off, so it can now be used from projects with stricter settings without causing Hack errors.

migrates to preg_match_with_matches()

Adds missing 2nd argument to \apc_fetch() (optional before HHVM 4.17).