Changes to how fixtures are handled

I've been looking to improve support for Fixtures over the last couple of weeks, not least because we are using text and image fixtures (via the img-fixture tag) heavily in a couple of new projects. This release changes the approach to how fixtures are saved to reflect the latest release of ContentEdit 1.3.0 which means that the html() output for fixtures now includes the outer html not just the inner.

IMPORTANT If you're not currently using fixtures this change wont effect you, if you are then this change is breaking and will mean that content saved as fixtures will no longer work as only the inner HTML will currently be saved but the outer HTML is now required.

Fixtures have always been a little experimental and this latest release is a step towards a more stable interface for them.

New features

• You can now inspect and changes the attributes for fixtures within the inspector (this is experimental).
• You can now disable the the alerts on cancel/refresh by setting the ContentTools.CANCEL_MESSAGE to null (#269 - thanks to all who requested this).