* Remove CleanWebpackPlugin
This pugin would wipe the non-minified files every time `make dist` was called,
and generally made it more difficult to build only particular files.
* Use order-only prerequisites for the `dist` Make recipe
This allows more efficient building because order-only prerequisites
don't force a rebuild of the main recipe.
https://www.gnu.org/software/make/manual/make.html#Prerequisite-Types
Still lacks inter-tab communication to update state across tabs, i.e.
when sending a 1-on-1 message in one tab, it doesn't appear in another,
because that information is not available via the websocket connection.
- Create a new `Connection` class that extends Strophe.Connection and
move related code from `converse-core.js` into this class.
- Store the session in localStorage when using a worker
- Move XEP-0156 code to connection.js
This allows us to initialize the connection without needing to know the
domain.
