membership#27 Update outdated membership statuses in preProcess rather than submit

Per membership#27 the function fixMembershipBeforeRenew is agreed to be a useful part of this flow
(ie we should set to expired before renewing if that is the correct pre-renewal status). As discussed on that
issue this moves that handling to the pre-process function.

In the process I hit what appears to be an unreleased regression affecting fixMembershipBeforeRenew borking
when changeDate = NULL from https://github.com/civicrm/civicrm-core/commit/2cb6497039fde605f5d64b2fe4fa0548cd5d1e07#diff-f43c8498e32f5b2d68ab27bcd243ca36L1136

The regression only affects master