Turn on caching for live errors and signature help requests by default
Turn on caching for live errors and signature help requests by default

Reviewed By: gkz

Differential Revision: D28367296

fbshipit-source-id: 64f994a3df611f96d0f3aaf3eab3657efa014d2a

facebook/flow,facebook/flow,facebook/flow,facebook/flow,mroch/flow,mroch/flow,facebook/flow,mroch/flow,facebook/flow,mroch/flow,mroch/flow,mroch/flow,mroch/flow,facebook/flow