- error callback for loadHistory, to make the reload button enabled again after an error
- remove descriptionEdit's placeholder (for compatibilty with earlier versions of Qt)
- add placeholder text to descriptionEdit if supported by the user's version of Qt
- set contentEdit read-only while loading a new page
- saveButton was still showing "Saving" after saving had failed
- The 'save' button is disabled and shows 'No changes' at first. Editing contentEdit's text
enables the button and makes it show 'Save'.
- The 'save' button is disabled and shows 'Saving...' when the page is being saved, and stays
disabled until contentEdit's text has been changed again.
- The 'save' button shows 'Saved' once the page has been successfully saved. fixes#560
- contentEdit is readonly when the page is being saved
- content preview's html code is now cleaner
- ICapContent.preview_content() renamed to ICapContent.get_content_preview()
- tab "preview" was shown first when starting qwebcontentedit. Fixed.