Adding Codiva.io Online Java Compiler and IDE to the existing users list.

This will highlight some of the advanced usage of Codemirror

- Multiple Tabbed editor
- Continuous compilation in the backend
- Autocompletion
- Mobile friendly
- Read-only mode

Closes #5047

See https://github.com/codemirror/CodeMirror/commit/79d266e60a8d02a865c7cf9340628a0f5d920394#commitcomment-25055107

Issue #5037

Closes #5036

That overlay modes can use to access the underlying token info.

The markdown mode uses `CodeMirror.innerMode` which isn't defined in
the stripped down node runmode. Since markdown is the only mode
(AFAICT) that uses it I'm not sure if it would make more sense rewrite
it to not use it but this seemed like the least risky option.

Issue #5031

Issue #5022

This will make it easier to get programmatic access to the content of these keymaps, per #5020

The addon would think it still was in a block comment when
one was opened and closed earlier on the line.

Issue codemirror/google-modes#58

Issue #3552

Issue #5016

Issue #5016

Issue #5013

To avoid bad parses when unary and binary operators are squashed
together without spaces.

Issue #5013

This is to prevent the closure compiler from failing with

bazel-out/darwin_x86_64-fastbuild/bin/polygerrit-ui/app/gr-app.js:51233: ERROR - Bad type annotation. expected closing } See https://github.com/google/closure-compiler/wiki/Bad-Type-Annotation for more information.
     * @return {Object{from:number, to:number, line: number}} The boundaries of
                      ^
  ProTip: "JSC_TYPE_PARSE_ERROR" or "checkTypes" can be added to the `suppress` attribute of:
  //polygerrit-ui/app:polygerrit_ui_closure_lib
  Alternatively /** @suppress {checkTypes} */ can be added to the source file.

1 error(s), 1 warning(s)

Closes #5009

Since it produces orderings that don't correspond to what
the browser does then.

To take document direction into account

Happened if you entered visual block mode in one editor and then tried to exit insert mode in another, since lastChange comes from vimGlobalState.

Closes #4999

When submitting the previous commit, I had not noticed that the parameter allowAtxHeaderWithoutSpace had type Object instead of type boolean. I've fixed this now.

Adding documentation for the `allowAtxHeaderWithoutSpace` configuration parameter.