Fixes bug #2156 for the most part

indention was bugged because it was reaching a wrong state when
any text that was not in the known set of words or patterns was
incurred.

for eg:
	head
		| <---- cursor should be here

and lets take  color : red as another example
now 'red' is same to the current tokenizer as 'head' from the first
example. So it indents for red automatically.

It was fixed by not letting any text after colon to reach the state
where it appends an indent after it.

Issue #3009

Issue #3009

To work around a layout quirk in Firefox

Issue #3009

Code that overrides this will break the new scroll model.

Issue #2984

Issue #2967

- line.handle.gutterClass is successfully
- Gutter class is removed from Markup

Amending removeLineClass to remove gutter class from markup.

See http://discuss.codemirror.net/t/possible-bug-in-simple-mode-indenting-behavior/109

Issue #2995

So that => in a string or comment doesn't trigger weird indentation.

Closes #2993

Issue #2997

That's what the parser configuration object is for. Also,
I am unsure how this was supposed to even work.

Issue #2996

Issue #2991

Fixes #2470

Also cause widgets with addWidget to have their events ignored.

See http://discuss.codemirror.net/t/click-to-clear-marker-created-with-cm-addwidget/98

Also turn off reindentation inside strings and comments.

Issue #2980

Issue #2976

Closes #2983