[Fedora-spins] new comps feature pushed

[Bill Nottingham]

Recently landed in yum/anaconda is the ability for an installation
environment's add-on groups to be selected by default when that environment
is selected for installation.
(related to https://bugzilla.redhat.com/show_bug.cgi?id=924061)

This is done by changing the option entry in comps from:
	<groupid>foo</groupid>
to:
	<groupid default="true">foo</groupid>

I'm sending this to the spins sigs, because certain spins might
want to change their environment that's used by anaconda to take
advantage of this. For example, the XFCE spin includes the
@xfce-apps and @xfce-media groups as part of their mandatory groups;
they could be moved to just being default options. Similarly, the
LXDE spin could mark some of their options (lxde-apps, lxde-office, etc)
to be selected by default when LXDE is selected.

Just FYI, and sorry about the delays (the yum build was in updates-testing
until the beta freeze was over.). Note that due to string freeze we
really can't create *new* groups to take advantage of this for F19.
 
Bill