* delsubstvar() and the last parameter to addsubstvar that makes it remove
a string are not used in debhelper itself, but have been left in the
library in case other things use them. Deprecate and remove.
-* dh --before , --after , --until , --remaining
+* dh --before , --after , --until , --remaining (not formally deprecated yet)
* debian/compress files
Also, grep the entire archive for all dh_* command lines,