Add support "package types" to dpkg-shlibdeps. Patch by

Add support "package types" to dpkg-shlibdeps. Patch by
Joey Hess. Closes: #345475

* scripts/dpkg-shlibdeps: Add possibility to
  specify a package type in the shlibs file
  and add a -t switch to dpkg-shlibdeps to
  specify the wanted type. Entries without
  package type will have type 'deb' and will
  serve as fallback if no entry with the
  correct type is found
* man/C/dpkg-source.1: Document new -t
  switch for dpkg-shlibdeps