Merge pull request #21 from gbastien/master

Stay compatible with IE < 9
doc: history
Preparing release 3.6.11
Back to development: 3.6.12
Merge remote-tracking branch 'collective.ckeditor/master'
Resolved conflict

Merge branch 'master' of https://github.com/gbastien/collective.ckeditor

Conflicts:
	docs/HISTORY.txt