update_modprobe_conf.sh don't try to read a non-existent file

Check for the presence of /etc/modprobe.d/modprobe.conf before trying to
read it
Merge remote-tracking branch 'origin/ubuntu-12.04' into ubuntu-13.04
Merge remote-tracking branch 'origin/ubuntu-13.04' into ubuntu-13.10
Merge remote-tracking branch 'origin/ubuntu-13.10' into fedora-20
verify_branch try to get a git checkout if one doesn't exist

If the user downloads the source code as a zip file then there is no git
repo.  This is a problem because they usually download the source on the
master branch.

If we're not in a git repo, we'll try to install the dependencies and
create a git checkout (with permission of course)
Merge remote-tracking branch 'origin/ubuntu-12.04' into ubuntu-13.04
Merge remote-tracking branch 'origin/ubuntu-13.04' into ubuntu-13.10
Merge remote-tracking branch 'origin/ubuntu-13.10' into fedora-20
verify branch if user downloaded a zip of the code but downloaded from
the right branch, we need not set up a git repo
Merge remote-tracking branch 'origin/ubuntu-12.04' into ubuntu-13.04
Merge remote-tracking branch 'origin/ubuntu-13.04' into ubuntu-13.10
Merge remote-tracking branch 'origin/ubuntu-13.10' into fedora-20
Merge remote-tracking branch 'origin/fedora-20'

Conflicts:
	verify_branch.sh