[PATCH] install-boot.sh support for rhgb

[Essien Essien]

[seems i sent a mail without the attachement already?]

the attached install-boot.sh looks for rhgb in the livecd temp build
directory, if installed, it appends it to the kernel line.
also, i've added 'quiet' to the main kernel line but not to the 'test'
kernel line.