[Debian-med-packaging] Bug#840912: Add minizip dependency to gwyddion

[Nicola Ferralis]

Package: gwyddion
Version: 2.45-1

Gwyddion uses the minizip library to work with zip-compressed files
such as .plux.  Minizip is widely available because it comes with zlib,
a base compression library used just about everywhere in everything. 
Yet, it is not a required nor recommended dependency in the debian 
gwyddion package, which makes the feature of opening zipped packages 
missing in debian.

Adding a simple dependency to libminizip-dev in the control file seems 
to work. Tested on several versions of Ubuntu.