v0.7.23

Maintenance release.

• Fix test failures against newer breezy/vcsgraph (#219)
• Bump debian-control to 0.3.12 (#217)
• Bump patchkit to 0.3.0 (#216)
• Bump debian-changelog to 0.2.22 (#213)
• Bump debversion to 0.5.2 (#209)
• Bump log to 0.4.31 (#214)
• Bump ctor to 1.0.6 (#206)