[build] Use git log when building the ChangeLog
[build] Use git log when building the ChangeLog

Instead of using a local script, use git log to build up the ChangeLog
file. This will allow valid dists on boxes different than mine.

GNOME/unique,GNOME/unique,Distrotech/libunique,GNOME/unique,Distrotech/libunique,Distrotech/libunique