Add tutorial: setting-up Bluetooth - PulseAudio

Probably needs more work, but this is a good stage to ask for comments.
On Windows the `tutorials` page did not look OK:
![tutorial_on_win7](https://cloud.githubusercontent.com/assets/8142081/5077594/11e1ed2a-6ea5-11e4-9b5d-810e3c4345cd.png)

But that could well be a jekyll on win artefact.

Should spell out "Headset profile (HSP) or Hands-free profile (HFP)". Also, "note 2" is not a note, it is just a link, so just make the whole sentence a link.