Added Support for .cib Managed View Controllers

[Justin Mecham]

I've added to nib2cib and CPViewController support for view
controllers that are managed by your nibs/cibs as well as supporting
some additional keys for NSViewController archiving.

To use it, add a new NSViewController instance to your nib file, set
the class name to your subclass of CPViewController and set the "Nib
Name" (in the View Controller palette) to the name of the nib/cib for
that controller (minus the .xib/nib/cib extension).

http://github.com/jsmecham/cappuccino/commit/5fe69a10e950d4c629fc06f24af5dffa79d72fe5

The additional NSViewController keys were implemented here:

http://github.com/jsmecham/cappuccino/commit/d09c46b9531bd89434b824763d077bb10fc80dea

I think that rounds out the keys for view controllers. I also fixed a
small issue that boucher pointed out in IRC where NSViewControllers
were being archived as CPCategoryViews:

http://github.com/jsmecham/cappuccino/commit/e66a8fc3323becd21b2002e48e7f64624b556f38

Hope you find them useful. Thanks,

Justin