Make POST for bulk delete actually work

Change-Id: I568e7e31df3dcbeac20dba6d543a13c0409de00e
Closes-Bug: 1232787
Allow programmatic reloading of Swift hash path config

New util's function validate_hash_conf allows you to programmatically reload
swift.conf and hash path global vars HASH_PATH_SUFFIX and HASH_PATH_PREFIX
when they are invalid.

When you load swift.common.utils before you have a swift.conf there's no good
way to force a re-read of swift.conf and repopulate the hash path config
options - short of restarting the process or reloading the module - both of
which are hard to unittest.  This should be no worse in general and in some
cases easier.

Change-Id: I1ff22c5647f127f65589762b3026f82c9f9401c1
Merge "Make POST for bulk delete actually work"
Merge "Allow programmatic reloading of Swift hash path config"