Rename 'event' to 'hangout'

[annapapitto]

I believe that 'event' is an overloaded name. Even my vim editor is telling me that 'event' has special meaning in javascript by coloring and bolding it. In my opinion, naming these 'hangouts' would be more specific and consistent with the command that stores them.

[marwahaha]

It's not a reserved word per se, but it is used as a special word in browsers.

I do think the concept of hangout does generalize to event (i.e. exercise, doing laundry, etc), but I like the phrasefriendlog hangout..

I think a PR for this is fine.