Squashed 'plugin/floo/common/' changes from 2cf6293..ac12ed2

ac12ed2 Fix permissions when sharing publicly. Give feedback when leaving a workspace.
ef5d559 Respond to pings with pongs.
c2e9990 Do a better job of matching paths. Bump protocol version and plugin version. Normalize persistent.json on startup.
d54857d Re-work create workspace to use new api.py
726989c Start of refactored and cleaned-up create_workspace/share_dir.
c94b464 get_workspace_by_path() now takes a filter function
7944e29 Python 3 ism
f9cc488 Don't show prompt if user doesn't have request_perms permission. Fixes #164.
5ad3354 If someone puts http:// in the address bar, connect over https unless we're debugging.
0a5fea3 Call reload settings on handler init. This prevents an exception if we update status msg too quickly.

git-subtree-dir: plugin/floo/common
git-subtree-split: ac12ed29ea6184c1424f642bffc30fcef8a87eb2
Merge commit '35548eabe9d942f2912bd8d825875d80405d02e2' into merge_common_python