This way, only one char's left and right edges are used, instead of its
(logical) neighbour's right edges.

In bidi content, this avoids trying to scroll to two logically close,
but visually far apart positions in some situations.

Issue #4824

This reverts commit e7b737c8.

This prevents the test case search_expandingCaseFold from hanging in
Firefox 54 on Linux.

See https://discuss.codemirror.net/t/gfm-mode-doesnt-seem-to-respect-codeblock-mode-specific-indentation/1286

Issue #4819

into a form that CodeMirror can understand.

Ref: https://www.postgresql.org/docs/10/static/sql-keywords-appendix.html

Issue #4784

Issue #4787

Since moving the highlighting frontier forward when doing
things like getTokenAt is not safe at all.

Also properly update highlighting frontier when a change
happens.

Closes #4813

This way it can be included more easily with javascript bundlers like
browserify/sheetify

Issue #4809

Issue #4803

Default this to true when the fat-cursor style is active.

Issue #4803

leave the old one for now

Issue #4800