MacGui: Advanced Tab initial implementation

MacGui: Advanced Tab initial implementation
- Sets groundwork for more robust x264 advanced options implementation
- currently strings are displayed and editable via textfield for x264 encodes
- for right now, the x264 string from preferences is ignored, need to figure out best way to implement that string.
- New Preset now takes the value from that field in advanced, negating the need for the field in "Add new Preset" window.

- NOTE: this also implements the new "Use Picture Settings" in presets to allow for "None", Use Current","Use Max from source".

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@556 b64f7644-9d1e-0410-96f1-a4d463321fa5