Created UserMediaService for use throughout Pulsar.

FE:

- services/user-media.js added to host calls to getUserMedia() in a
central and managed place able to provide access to user media
universally throughout the app

- index altered to load services/user-media.js

- /conversations route altered to prototype in a <video> element with a
live video stream (does not yet talk to other hosts)

Quick CSS Fix:
- pulsar-pulse.less altered to add position:relative to .heading-wrap.
This is why titles were overflowing their bounds by a bit in the /pulses
route