first pass at changing the model
refactored heartbeat calculations
cleanup
a few logic fixes
Permalink metrics mostly working now, though UI is not styled.
Did a bunch of admin permalink styling. Still chasing a weird issue with time accumulation.
Fixed a minor bug with initial conditions on time accumulation.
Sorting sessions by connected count first, then total user-seconds.
Added link to shortcode.
Resolved merge conflict.
Merge pull request #135 from drewww/permalinkAdmin

Permalink admin