Revert "missing include - TAR_COMMAND was undefined"

This reverts commit 5f8f791b7bb9ea992c652d2171aa9a19903bd274.

The env Makefile is used to generate the vars file, but by including
makefile.inc, a dependency on these variables is introduced.

The undefined reference to TAR_COMMAND still has to be resolved, though.
Fix innocuous typo
Don't download transmart-loader all the time
env: remove support for dl ts-loader from files.thehyve