Placeholders don't clear properly

[treet]

In some cases the placeholders will not be cleared upon leaving the edit mode.

How to reproduce:

1. Run any createjs example with a placeholder, such as https://github.com/bergie/create/blob/master/examples/example-geo.html
2. Click Edit, remove the text in the header ("c-base Spacestation"), Save and Cancel.
3. Click Edit again, and immediately click Cancel. The placeholder "[schema:name]" will remain.

Note that the placeholders will get cleared correctly if you first made an edit somewhere in any editable field (anything that enables the save button) before clicking Cancel.