MacGui: fix a bunch of regressions (various crash when in some textfields, encode log going to the wrong directory).

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6676 b64f7644-9d1e-0410-96f1-a4d463321fa5
MacGui: fix the picture and filters summary in the video tab.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6677 b64f7644-9d1e-0410-96f1-a4d463321fa5
MacGui: hide the iPod 5g check box if the codec is not h.264.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6678 b64f7644-9d1e-0410-96f1-a4d463321fa5