[go mode] Set Go mode to use brace folding
Prevent overlay token types from showing up in getTokenTypeAt output

Issue #2457
Refines the text selection detection in readInput function.

This change is for enabling the display update while inputting text via the input method.
Fix context menu select-all in IE11

Issue #2463
Be more accurate about which handlers to fire change events for

I.e. don't fire for a handler that wasn't registered when the change happened.
Be more precise about which cursorActivity handlers to fire

Issue #2464
[css mode] Fix tokenizing of empty url() token

Issue #2465
Guard against NaN when computing horiz padding

Issue #2467
Call cursorActivity handlers after other handlers

To preserve existing change/cursorActivity handler ordering
[r mode] Remove license link

All of the distribution is under a single license.
Merge branch 'master' of https://github.com/marijnh/CodeMirror