Replaces our vendored dependencies with dependencies on packages
installed from NPM. This makes it substantially easier to find out
what versions of 3rd-party packages are installed, and substantially
easier to upgrade them as and when necessary.

Libraries have been installed pinned at the version available on NPM
nearest that installed in the repository. This means:

- angular remains v1.2.28
- angular-animate was upgraded from v1.2.25 -> v1.2.28
- angular-resource was upgraded from v1.2.25 -> v1.2.28
- angular-route was upgraded from v1.2.25 -> v1.2.28
- angulartics remains v0.17.2
- bootstrap remains v3.3.5
- jquery remains v1.11.1
- jstimezonedetect remains v1.0.5
- moment remains v2.5.0
- moment-timezone remains v0.0.1
- ng-tags-input remains v2.2.0

Unfortunately, the following modules don't appear to be available on NPM
and so remain in the repository:

- angular-bootstrap
- angular-sanitize
- angular-toastr (at a version early enough)