git-unmerged is a tool to find commits that have not been merged into the upstream branches.
After basic configuration it will list every branch that is not merged
into some special branches (called release branches)

It supports having multiple upstream branches, and also an exclude list for branches that
aren't intended to be soon.

You configure this tool with the following git keys:

unmerged.releases
	These are the branches that are considered as release branches.
	Separate them with spaces

unmerged.exclude
	If you want to exclude any branches from the output, then list them
	here separated with spaces. Optional.


For example you could put the following into your projects .git/config to
list every branch that is not merged into any of master, r/v1, r/v2
branches, but exclude the 'attic_foo' and 'attic_bar' branches even if they
aren't merged:

[unmerged]
	releases = master r/v1 r/v2
	exclude = attic_foo attic_bar