Merge r409942, r607245, r607440 from trunk:

* Remove temporary files if renaming fails, otherwise they may accumulate.


* Make loglevel consistent for similar situations. As this really should not
  happen set it to error.


* Change loglevel from ERROR to WARNING if the renaming of the vary, headers
  or data file fails.

Submitted by: Davi Arnaut <davi haxent.com.br>
Reviewed by: rpluem, niq, wrowe


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@607443 13f79535-47bb-0310-9956-ffa450edef68