Merge pull request #909 from jmaas/master

PEP8 - cobbler/modules/scm_track.py
Merge pull request #910 from jmaas/master

PEP8 - cobbler/modules/manage_tftpd_py.py
Merge pull request #911 from jmaas/master

PEP8 - cobbler/modules/manage_isc.py
Merge pull request #912 from jmaas/master

PEP8 - cobbler/modules/manage_in_tftpd.py
Merge pull request #913 from jmaas/master

PEP8 - cobbler/modules/manage_import_signatures.py