jpeg changes

[Joshua Root]

Dependencies on the jpeg port have been changed to libjpeg-turbo, and 
the ports declaring them have been rev bumped due to a differing library 
version. Please keep an eye out for ports that link with libjpeg without 
declaring a dependency (rev-upgrade should notice them). If you find 
any, please rev bump after adding a dependency like this:

path:include/turbojpeg.h:libjpeg-turbo

(Doing it this way allows mozjpeg to fulfil the dependency as well.)

Thanks,
Josh