C<4.0/fail-taint-mode-early>. A feature branched from C<master> when
there exists a C<4.0-trunk> but no C<4.2-trunk> might be named
C<4.2/rename-LogToScreen>. For consistency, branches should use dashes,
-not underscores, to separate words.
+not underscores, to separate words. Branches which are destined for
+4.2, but which are branched from 4.0 (to provide for easy extraction as
+a 4.0 extension) should be named 4.2-on-4.0/branch-name.
Branches should be reviewed by another developer before being merged.
Reviewers should make sure that the branch accomplishes what it claims