Raspberrypi 7" display enclosure

First attempt on designing a functional tablet based on the raspberrypi 2 model B, the official raspberrypi 7" display and the official raspberrypi camera.

based on [MCM Electronic's Raspberry Pi Tablet shell](https://github.com/MCMElectronics/Raspberry-Pi-Tablet)

this is a work in progress at early stages - i didn't choose yet the battery system, for example.

###UPDATE Nov. 16th 2015
- Managed to do a test print and found several measurements to be fixed.
- Uploaded a new version wi