No need to show Twitter image when OpenGraph is showing

Both the description within the PR, and that next to the `image()` method suggests that it doesn't need to be called when OpenGraph is also showing. Using the Twitter Card Validator confirms that when `twitter:image:src` isn't present, it falls back to using `og:image`.
Instead of sorting the terms by name, sort them by term_order of their oldest ancestor
First element bugfix
Merge pull request #160 from tacoverdo/master

jQuery-function .live() is deprecated, updated to new function .on()
Merge pull request #151 from GaryJones/patch-1

No need to show Twitter image when OpenGraph is showing
fix for terms that don't have term_order
Merge pull request #158 from Gaya/master

Fixed sorting of taxonomies in breadcrumbs to go for term_order instead of name