Incorporate our fork of the cordovaHTTP plugin.

Make sure that uninstall of the cordova file plugin is after everything
else - a couple of things depend on it, including teh cordovaHTTP plugin.
Incorporate cordovaHTTP, when present.

Integrated with the alternateAjax provisions, and with fallback to
$.ajax if cordovaHTTP is not present. Specifically:

1. Prefer "alternateAjax" function designated in settings, if any.
2. Otherwise, use cordovaHTTPAjax if present - it depends on the cordovaHTTP
   plugin.
3. Otherwise, use $.ajax.
4. There is no 4.

Since we fallback to $.ajax, the tests will still work on the desktop.
Whoops, missed a small comment edit.
Rectify spiderOakApp.ajax() docstring typo and clarify the text.
Notify users that mobile app logins are not ZK.

They are notified of this every time they try until the first time elect
to continue, and then they are not notified again.

The notification happens before their credentials are sent.
Use "Zero-Knowledge" per emerging convention.

Also, streamline some phrasing.
Twiddling.
Is done.
Quote 'Zero-Knowledge' to Follow style rules.
Certificate pinning and privacy screen plugins

Also an update to the cordovaHTTPAjax function
The actual public certificates
extraneous cert
Move enabling cert pinning to device ready

Also cleans up the error display...
Merge pull request #575 from SpiderOak/cordovaHTTP-plugin-adapt

Certificate pinning and 'Zero-Knowledge' warnings