Adds checkbox property to Camera to open the front-facing camera.

Squashed commit of the following:

commit 834f04ca02d30ef734c2c018a49954b8b512f6a4
Author: Mark Sherman <msherman@cs.uml.edu>
Date:   Thu Feb 6 22:40:50 2014 -0500

    Adding option to request front-facing camera.
    Added default value to new property.
    Updated documentation to match.

    Change-Id: I445d9fc696005973ff1ac87ca99e2c90658d56f5

commit bfe5138e57ea7118e61340687f6284d3c15a299f
Author: Mark Sherman <msherman@cs.uml.edu>
Date:   Thu Feb 6 22:40:50 2014 -0500

    added default value to new front-facing property of Camera

commit 6f23a9decbb888fe53d5d8e68fedd55d64fa5e0e
Author: Mark Sherman <msherman@cs.uml.edu>
Date:   Thu Feb 6 22:23:34 2014 -0500

    Added checkbox property to Camera to open the forward-facing camera.

Change-Id: I18780f1bedd27266b02d40f90a3079f42e6792ec