Revision history for namespace::clean::xs.

0.05 Sat Apr  2 13:18:40 MSK 2016
    - fix explicit cleaner for non-sub entries
    - perform more thorough cleanup for leftover globs

0.04 Thu Mar 17 02:41:57 MSK 2016
    - workaround rt#127708

0.03 Mon Mar 14 21:15:46 MSK 2016
    - set namespace::clean compability version

0.02 Mon Mar 14 20:08:41 MSK 2016
    - speedup storage lookups by using preshared keys
    - fix compilation in c89 mode
    - threading tests

0.01 Mon Mar 14 00:43:39 MSK 2016
    - initial release