distro_signatures: add SLES11-SP3

Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
newtests/suse_import_test: add SLES11-SP3 information

Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Allow for easy relocation during make install

Introduce standard make semantics of DESTDIR to install into a different
root. This is often used by packagers, so we're adding this convinients
to everyone's benefit!
BUGFIX: return 1 when no MAC is passed to mac_exists()

If an interface doesn't have a MAC, mac_exists() is called with an
empty string that returns a list of all interfaces names.  Instead,
return 1 from the function so that the "network" line is not
generated.
Merge pull request #615 from aronparsons/skip-nic-with-no-mac

BUGFIX: return 1 when no MAC is passed to mac_exists()
Merge pull request #411 from nacc/add_sles11sp3_signature

distro_signatures: add SLES11-SP3
Merge pull request #622 from jmaas/master

Cleanup legacy codes.py usage.
Merge pull request #602 from igalic/destdir

Allow for easy relocation during make install