Remove the output parameter from CalledProcessException

CalledProcessExcpeption does not accept this parameter in python 2.6.

Resolves: rhbz#1054048
New version 0.7.7
Revise the preupgrade HIGH risk message.

Modify the high risk check to ask the user to continue. Include the
risks in the output. Use the return value of preupg to determine whether
riskcheck data is available to avoid having to know the path of the
xccdf file.

(cherry picked from commit 19bc6bd3f52e1f5676954b8c04c2775dec02d663)

Related: rhbz#1059447
Merge branch 'old-riskcheck' into old (#1059447)

This merges in changes for integration with preupgrade-assistant.
New version 0.7.8
Merge branch 'old' into old-extrabuilds

Sync to redhat-upgrade-tool-0.7.8. The build for 0.7.8 contains the
preupgrade-assistant integration changes that were built as 0.7.6.1
Require --instrepo with --network.

RHEL has no default mirrorlist and upgrades through CDN are not yet
supported, so require that --network specifies where that is.

Resolves: rhbz#1070080
Handle missing version arguments

Workaround the different handling of missing arguments between argparse
and optparse.

Resolves: rhbz#1069836
Fix the reboot command for RHEL 6.

systemctl? That's not gonna work.

Resolves: rhbz#1070821
New unofficial version 0.7.8.1