add link to new mailing list
prepare release
added the changelog for 1.0b1
fix mailing list link
vb
watcher callback invalid only if None
add test for weird watcher
Merge pull request #56 from prezi/watcher-callback-invalid-only-if-none

watcher callback invalid only if None
add changelog entry to #56
choose ports 0, 10, 20, 30... and not 0, 10, 30, 60, ...
Queue with item locking recipe
Added LockingQueue to CHANGES
LockingQueue: fixed tests and documentation
LockingQueue: added test precondition to use ignore ZooKeeper v < 3.4, removed 'ascii'
LockingQueue: refactoring after code-review
Merge pull request #59 from skd/master

Added a LockingQueue to recipes. When get() method is called this queue locks an item instead of removing it.