Allow manually adding hardware to user

[GDay]

This adds a button on the colleagues detail page to manually add hardware to a user. This will not create to do items for any other colleagues to fulfill this. This is intended to be used for existing colleagues that already have hardware, which just need to be registered.

[coveralls]

coverage: 89.726% (+0.02%) from 89.707%
when pulling ed9f224 on allow-manually-adding-hardware
into 8a4eee6 on master.