Unzip/untar on Linux should be into like-named directory, not dumped in cwd

[markstock]

When unzipped, most zip, tar, bz2 archives create a new directory named the same as the zip file. When that doesn't happen, a user's cwd gets polluted with a bunch of files and dirs - not fun. Please use the nicer standard of putting all contents into a new directory.

When I tar -xf tropy-1.16.2-x64.tar.bz2 I should get a self-contained directory called tropy-1.16.2-x64.

An added advantage is that a user can install multiple versions next to each other without renaming directories.

[inukshuk]

You're right. We'll adjust the packaging scripts.