bump leap.common min required version, new change needed
'collect_plugins'.

master and develop "diverged" because a merge commit, this moves us
back to good track.

When trying to use an unexisting list function, to alter a view, the error is
not a missing document error, but an obscure "TypeError" saying that "point is
undefined" because of the way the javascript code in couchdb server tries to
find the list function.

This commit adds a catch for that error and raises the proper exception in the
soledad couch module.

HTTP client cached connections will hang around in the reactor if they are not
properly cleaned up, and might raise a "reactor unclean" message on shutdown.
This commit adds a close() method to the client http target that will cleanup
those connections.

Using real uuid to separate Locks on each test allow them to
be run in parallel. Using real uuid also allows parallel syncs.
This is being done to allow test suite to run in parallel on future.

after suggestions in the review