Creates a $HOME/.zopen-config file via zopen-init (we could potentially call this via zopen-setup as well).
zopen download has been updated to download and check for installed software based on the $ZOPEN_SEARCH_PATH defined in $HOME/.zopen-config.
zopen build has been updated to search dependences based on the $ZOPEN_SEARCH_PATH defined $HOME/.zopen-config.
Also fixed a bug when zopen build -u is specified and the .env is sourced twice. This result in a linker issue with libraries that export ZOPEN_* envars.
Also, allow our z/OS Open Tools Git as a dependency now that it is functional
$HOME/.zopen-config.$HOME/.zopen-config.