Closes #3141

We're still targeting ES3.

Issue #3095

Issue #3089

Closes #2323

Closes #2983

The code was confused beyond belief, and the hintWords
functionality will provide the same completion power
without loading an additional addon.

Completing inside a word used to try and take the whole word into
account. This is not typical completion behavior, and often not what
you want. After this change, the addons only take the part of the
word in front of the cursor into account.

Defaults to `window`

See http://discuss.codemirror.net/t/html-hints-not-working-just-after/45/6

- Takes `defaultTables` as optional option and hint columns from that
table without explicitly mentioning table name.
- Update doc/manual.html for sql-hint addon.

Signed-off-by: Nisarg Jhaveri <nisarg.jhaveri@research.iiit.ac.in>

Signed-off-by: Nisarg Jhaveri <nisarg.jhaveri@research.iiit.ac.in>

To make it easy for client code to color completions without clashing
with the selected styling.

Closes #2761

Issue #2663

Bumping them for every release just adds too much git
noise and history blowup.

Closes #2482

Issue #2406

Summary: If `options.async` is enabled, it's possible for `activity` to
be called a second time before the first call's paired `finishUpdate` is
triggered. Then, when the second call to `finishUpdate` happens, the
still-active widget in `completion.widget` is unceremoneously
overwritten and can now never be closed. This leads to a lot of weird
and broken behavior, notably an autocomplete window in the browser that
never goes away and can insert its text over and over and over.

Test Plan: This is really hard to trigger. My project consists of a
webworker providing autocomplete, which has some latency before it calls
the `finishUpdate` callback. But it depends on the exact latency and
even the user's typing speed to whether things happen in just the right
order. I basically just added and deleted characters with the
autocomplete prompt open a bunch until it eventually reproduced. After
applying this patch, several minutes of bashing didn't trigger the issue
again.

Add tests. Adjust addons that depended on previous token structure.

Also improve indentation around implicit end tags in HTML.

Issue #2176
Issue #2333

It was broken and confused.

Make the mode register a list of completable words instead.

Issue #2324

Issue #2323