Refresh with hosted apps installed outside of dash
Moved appNotFound logging to appNotFound handler
_ensureInstallable modification + code cleanup

_ensureInstallable now delegates to AppsUtils::checkManifestContentType
to see if an app is installable. _ensureInstallable also needs to check
for http:// in order to prevent non-hosted apps from returning installable.
Made requested changes
Fixed typo preventing apps from running on refresh
Merge pull request #573 from bkase/refresh-hosted-app

Refresh hosted apps installed outside of dashboard. Fixes #443