[LDView] LDView 4.4 Alpha 6 test release

[Travis Cobbs]

Thanks, will do.  (What's the difference, if any, between the two?)  In the meantime, I wanted to report that the ldview-qt5-4.4a6-ubuntu-20.04.amd64.deb installs/works on Linux Mint 20 - no complaints from package manager, no need to run sudo apt-get install -f.

The osmesa version is the command line-only version that is used purely for generating images.