dropping libtiff4-dev transitional package

[Jay Berkenbilt <qjb@debian.org>]

There are 27 packages (including 1 "pending upload") left that still
have build dependencies on libtiff4-dev:

https://bugs.debian.org/cgi-bin/pkgreport.cgi?tag=libtiff4-dev;users=qjb@debian.org

At this point, I'd like to go ahead and remove libtiff4-dev and change
these to "serious" since they will be FTBFS. I'm thinking most people
will probably fix their packages soon after this, and I can work on NMUs
for the rest after a little more time. I think we should act soon if we
want go get the libtiff4-dev transitional out of the archive before
jessie.

Any objections?

-- 
Jay Berkenbilt <qjb@debian.org>