adobe/CodeMirror2 — pull request #55 by jhatwich (2012-05-06 20:11:53+00:00)
Title: adding API isDirty()

the undo stack size is limited to a certain size so it is not reliable
to determine dirtiness. Adding a counter and isDirty API. This change
is in support of allowing undo to be able to set a document to a clean state.