update Debian files

Fixes the following Lintian tags:
```
W: mintupload source: debhelper-but-no-misc-depends mintupload
W: mintupload source: debian-rules-missing-recommended-target build-arch
W: mintupload source: debian-rules-missing-recommended-target build-indep
W: mintupload source: binary-arch-rules-but-pkg-is-arch-indep
W: mintupload source: ancient-standards-version 3.7.2 (current is 3.9.5)
E: mintupload: copyright-should-refer-to-common-license-file-for-gpl
W: mintupload: copyright-without-copyright-notice
W: mintupload: extended-description-line-too-long
```
Will be replaced with a symbolic link.