rpmbuild-in-dir: do "-ba" if only a .spec file is passed
yupdate-review: rewrite shell script in Python

Allow optionally passing the path to yum.log
add graphics-stack-versions
xnest: use 'xinit' instead of 'startx'

'startx' from xorg-x11-xinit-1.3.2-7.fc18.x86_64
no longer allows specifying the X server binary to use.