Should reduce the indentation issues after long lines

Issue #3443

- Provide custom list through CodeMirror hintOptions to kickoff
  autocompletion for domain specific usage.

Since the library is completely oblivious to module loaders

Issue #3447

For example:

body
  color $red

.content
  color #000

The .content was highlighted as the variable-2

Issue #3438

Closes #3417

Issue #3434

Also some general improvements to material.css and solarized.css

Don't treat backslashes specially inside of them

Closes #3428

Issue #3423

Issue #3421

Closes #3421

Closes #2645

Adding a CodeMirror option for controlling how long the ternTooltip should be visible before closing

... and export (via defineExtension) a method to explicitly trigger
linting from user code.

Closes #3409

Closes #3410