Unix CM: Tidy up the statistics interface

Unix CM: Tidy up the statistics interface

Sort out the function call statistics interface. Whilst it's still
wretched, this makes it a little less so.
*) Add some warnings at the start of the afs_CMStats structure about
   what needs to be done when adding things there
*) Remove the conditionals around the CacheBypass counters, so that stats
   clients don't need to be built with the same options as servers
*) Add all of the stats entries added after IBM to the xstat_cm_test
   routine
*) Add a warning to xstat_cm_test if the data returned from the server
   differs in size to the local stats structure.

Change-Id: If1ffb68c84bca972f685ae619febba8c6f8b5e17
Reviewed-on: http://gerrit.openafs.org/1319
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>