Fix double option creation

Addresses VA-42: "Pressing 'Return' over the 'Add Option' button creates
two options"

Both the trigger for button.data-bind and the row.keypress were calling
self.addOption, but the fields were only being reset after one of the
ajax calls succeeded.

Now, we wipe the fields before doing the request (unless the Name is not
filled in), preventing the second request from going through.
Remove unused projects
Fix missing System.Web.Http reference

We needed version 5+, but were only referring to version 4.0.0.0
Clear out unused files

Removes files from the projects which are no longer part of the build
Merge branch 'upstream' into develop
Removes admin page obscurity
Merge pull request #19 from tpkelly/develop

Fix double option creation
Merge pull request #20 from stevenhillcox/feature/admin-login

Removes admin page obscurity