[merge addon] Support passing in document objects as content
[merge demo] Remove layout-breaking css rule
[less mode] Fix a few more unsafe method calls on .peek()

Issue #2028
[xml mode] Rewrite state machine to be simpler and faster

Tangentially related to issue #2023
[xml mode] Reset state when giving up on a bogus tag

Issue #2023
[manual] Point to extension functions from addon section
[xml mode] Fix bug introduced by a6aa48eee2c8262a8763f1e39afdf8a79a130a41
Merge branch 'master' of https://github.com/marijnh/CodeMirror
hackity hack hack hack