Most modern browsers now keep displaying the placeholder even if the
user has focus on the input and only hide it when the input has content.

This change is to make this addon consistent with this, so users won't
tell the difference with native inputs' placeholder behaviour.

Issue #1972
Issue #1967

Issue #1969

Issue #1969

Issue #1908

Issue #649

Issue #649

Issue #1960

`cm-s-ambiance` and `CodeMirror-focused` are classes to the same
element, so search for `.cm-s-ambiance .CodeMirror-focused` will fail.

Issue #1947

It's possible to provide custom markup for hint elements that are LI
tags and that breaks event delegation logic that expects UL to have
text-only LI nodes. As a result if you have elements inside LI and
click/dblclick on those, nothing happens and selected hint is not
applied. The fix improves event delegation in the way to find nearest
parent element to event target that is a hint element at the same time.

Issue #1943

As a result, the common pattern

import (
	"foo"
	"bar"
	)

will re-indent automatically to the gofmt-blessed

import (
	"foo"
	"bar"
)

Closes #1925.

The C editor and the C++ editor have the same variable name, so
the latter shadows the former. Fixed by renaming both.

Closes #1920.

Remove callback argument, save currently open dialog in per-editor state.