Turning on warning as error on Linux

Turning on warning as error on Linux

Fixed the few remaining warnings and turned on warning as error on Linux.

Explicitly turned off warning as error in libjpeg, cityhash and json.
Committed: https://code.google.com/p/skia/source/detail?r=8067

[sugoi, 2013-03-08 17:50:39]

This current patch seems to pass the trybots, so it should be good to go.

[bsalomon, 2013-03-08 18:21:41]

On 2013/03/08 17:50:39, sugoi wrote:
> This current patch seems to pass the trybots, so it should be good to go.

I've got no idea about SkDrawExtraPathEffect but otherwise lgtm.

[reed1, 2013-03-11 15:59:14]

adding cary, who understands the animator code.

Your change seems right, in that w/o it all of the work to compute the
SkDrawMatrix seems to be for naught, but it is a functional change, and I just
don't know if it is right or wrong.

[caryclark, 2013-03-11 17:00:42]

(animator change) lgtm

[sugoi1, 2013-03-11 18:45:18]

Committed patchset #2 manually as r8067 (presubmit successful).