Wrapping CGContext in using() blocks. Squashed commit of the following:

commit 2897b346f2a98b0a76c89e62e36caa32043018eb
Author: Larry O'Brien <lobrien@knowing.net>
Date:   Wed Apr 30 09:39:17 2014 -1000

    WeatherMap sample: Wrapped CGContext in using()

commit 4f571659aa92f78dfaf3408f5a3a21d4a501c696
Author: Larry O'Brien <lobrien@knowing.net>
Date:   Wed Apr 30 09:12:25 2014 -1000

    Quotes sample: Wrapped CGContext in using()

commit 7511c14345bf542b70517a7ac472722fd376bc12
Author: Larry O'Brien <lobrien@knowing.net>
Date:   Wed Apr 30 09:04:53 2014 -1000

    QuartzSample: wrapped CGContext in using()

    I checked the implementations of the abstract DrawInContext() method and they were not individually guaranteeing cleaning up of the CGContext. So the wrap happens in the abstract QuartzView Draw() method.

commit 370c72054382caaad59fe649972ff850cbfeab2a
Author: Larry O'Brien <lobrien@knowing.net>
Date:   Wed Apr 30 08:59:19 2014 -1000

    PaintCode sample: wrapped CGContext usages in using()

commit f6b1ff047653465704bd7e74f308f00e3f6152ca
Author: Larry O'Brien <lobrien@knowing.net>
Date:   Wed Apr 30 08:47:58 2014 -1000

    AVTouch sample: Wrapped CGContext in using()

commit e0abb9f37485644a567d7d52bb2c1dcc3f111ec2
Author: Larry O'Brien <lobrien@knowing.net>
Date:   Wed Apr 30 08:47:41 2014 -1000

    FrogScroller sample: Wrapped CGContext in using

commit e9c732e7afe25a13b9cc11fbbe615580c533cd4f
Author: Larry O'Brien <lobrien@knowing.net>
Date:   Wed Apr 30 08:47:18 2014 -1000

    MotionGraphs sample: Wrapped CGContext in using()