When `_doDisconnect` is called in Strophe, `authentication` is set to
`false`, so reconnection wouldn't happen anymnore

Updates #1490

updates #2006

- Fix failing tests.
- Bump timeout for emoji tests
- Remove unused files.
- Update features section.

It's better to parse an incoming message stanza early, than to have
all kinds of methods throughout the codebase that does querySelector
etc.

Firstly, it allows us to catch and report errors and malicious stanzas early on.
It also simplifies programming because you don't need to try and
remember how to properly parse a stanza, all the work is done upfront
for you.