Introduced User/Group Classes

Setup some structures to hold our user / group data. Going to reduce
JSON calls and keep more on the client side and organized. Plan to get
a necessary json calls in and loaded into memory during login. Friends
of friends / anything deeper besides for just friends of logged user /
groups of logged users will need to be loaded in later, and will be
deleted during runtime when they are no longer needed (such as when you
go from friends list to friends profile to friends list again…)
#workinprogress
Merge pull request #69 from mierze/master

Introduced User/Group Classes