Module description - sessions/\*
================================
The sessions folder contains functionality that was broken out to keep
``sessions.js`` from getting huge.
addRemove.js
------------
Provides methods for adding, removing, and re-ordering sessions and
their tabs.
binding.js
----------
Event bindings, such as drag/drop and middle click
state.js
--------
Actual tab state as a singleton, imported by other modules to do
re-ordering or other tab manipulation.
switching.js
------------
Provides the utility methods for between tabs, directly or in order.
