Closes #4080

and remove autocomplete bindings

Closes #4085

See https://discuss.codemirror.net/t/range-error-with-scrollpastend-addon/773

Issue #4069

Issue #4078

It is, per https://golang.org/ref/spec#Predeclared_identifiers

Closes #4064.

Closes #3888
Closes #4063.

Issue #4038

Issue #4050

Closes #4056

Store the modifier in the original mouse event to choose between
move and copy drags.

Issue #2556

So that they don't interfere with clicking and dragging

Issue #2556

Issue #4057

Closes #4057

Use findMarks instead of findMarksAt in foldGutter.js to correctly
find marks when a single line is collapsed so that the arrow displays
correctly as collapsed.

Add option 'clearOnEnter' to foldcode.js and default it to true.
This option determines whether the marker added when folding a
line clears when the cursor enters it.

Closes #4042

See https://discuss.codemirror.net/t/width-of-sql-hint-dropdown-in-firefox-is-not-always-correct/757

It breaks document tree rebalancing.

Closes #4032

See https://discuss.codemirror.net/t/dynamically-switch-mode-with-sql-hint-addon-bugs/751

Closes #3796

Closes #3896