Alter "sampling time per cell" string
Replace GraphView class with a nicer GraphView lib
Make Tuples printable with toString()
Start using new GraphView from library

* See https://github.com/jjoe64/GraphView/ for details
Constantify some default SlidingMenu settings

* Extract default fragment to DEFAULT_FRAGMENT
* Extract the default "open menu" flag to OPEN_MENU,
  which can then easily be changed with a boolean-not