Quartz features now optional in cairo and pango

[Ryan Schmidt]

I just committed an update to the cairo and pango ports that make the  
Quartz features optional. Previously, they were always enabled. If  
you relied on Quartz features being available in cairo and pango, be  
sure to install both ports with the +quartz variant from now on. You  
may want to edit your variants.conf file and add +quartz to it so  
that this is automatically taken care of when you upgrade your ports.