CHANGELOG for version 0.11

Bug Fixes:
-In file list, the path or prefix was converted to boolean value. Fixed.

Changes:
1. Make astakosclient a mantatory requirement for kamaki [#4312]
2. Make post_user_catalogs obsolete, but keep for one more version [#4337]
3. Rename user commands for cached account requests as /user session [#4340]

Features:

1. Cache user catalog calls [#4337]
2. Implement separate methods for uuid2usernames and v.v. [#4337]
3. Move all methods from snf-astakos.py to astakos.py, with some renaimings
    astakos_quotas/uuid/username/authenticate --> user_quotas/uuid2username/username2uuid/info
    astakos_... --> admin_...
    e.g.,
    astakos_services --> admin_service, astakos_commission --> admin_commission
4. Implement OpenStack Network API 2.0, with synnefo/cyclades extentions. New:
   network info/list/create/delete/set
   subnet info/list/create/set
   port info/list/create/delete/set