noticed a missing required file for bootstap-ie7

Please do not merge unless you are Fran. Fixing this issue does seem to re-break many issues.

Noticed we where not loading boxsizing.htc which is listed an requirement.
https://github.com/coliff/bootstrap-ie7

However I suspect we may not need it at all do to loading Respond.js which also adds polyfill for min/max-width.