Upgrade to React 0.9.0

* Switch to react-with-addons to get children manipulation and
  "cloneWithProps"
* Generate gripped version of main JS file even though it's currently
  unused
* Clone children in TogglableTabsComponent to modify their props rather
  than modify them directly; The previous use of modifying their props
  no longer works (and wasn't a great direction anyway)
Avoid gzip -k option, which is unavailable on Travis
Merge pull request #179 from mesosphere/react-0.9.0-upgrade

Upgrade to React 0.9.0