Reorganisation

Changing repository structure so it is easier to access core files by
separatinng them from the example code.
Removed Rectangle

Removed the rectangle drawing code so that only a gradient spotlight is
produced around the designated area. The rectangle code was producing
an unappealing black rectangle.
#DS15: Added initial code to allow users to record a purchase order number for the job card.

Tweaked the UI a bit as well to better accommodate the new fields.
Fixed Memory Leak

_modalView was being assigned to nil without first calling release
causing a leak.