Remove libpopplerXX from the dependency list.

The right dependency on libpopplerXX is automatically set by ${shlibs:Depends}.
Remove libfontforge1 from the dependency list too.

It is also automatically set by ${shlibs:Depends}.
Remove libjpeg and libpng from the dependencies

as they are dependencies of libpoppler.
Merge pull request #346 from Rafiot/deps

Remove libpopplerXX from the dependency list. #341