Warnings from Preferences.app

Hi Jeff,

you did add the option -Werror in the subprojects of Preferences.app, 
whcih makes the compiler treat warnings as errors. This is normaly fine 
as it helps to focus on possible errors in the code. In this case it 
stops me from compiling this applications as you must be using a very 
old version of GCC to get your code through. There are at least two 
warnings for each file for GCC 3.3 (one about the use of import and one 
on the unused rcsid). That way no file can be compiled.
The use of -Werror during a development process is surely good practice, 
but when you release your code, you should remove it, as you never can 
tell how picky other peoples compiler may be.

Fred