mat 0.5.2

[MAT](https://mat.boum.org/) (<i>Metadata Anonymisation Toolkit</i>) is an application to remove metadata from files of various formats (PDF, PNG, JPEG, MP3, etc). It was originally written during the GSoC 2011 and is still actively maintained (the last release was one month ago). It’s available in Debian packages.

Note: I was not able to find a way to install `python-gi` and `python-gi-cairo` here, which are respectively required dependencies to have a GUI and a full PDF support. The CLI app still works without them.