Add default edit rate limit of 90 edits/minute for all users

Previously there was no rate limit at all if you were autoconfirmed.

This initial setting is set on the high end of things, we may
adjust later. See also T192668, T194204.

cf I7cb002900bae2da3f4f4758671186659c1720e1d

Change-Id: I23ddf58aae059ffe7f00af93b4fef5ab45bb987f