hwaf-env: rename section to define env.vars. env -> hwaf-env
init: drop -name switch as it is taken from 'extra' args
context: typo
setup: pick up configuration from -cfg option
pkg-co: implement git+ssh checkout
pkg-co: drop checkout packages as git-submodules. (how would this work with packages from git-repo, bzr-repo, ... ?). simplifies a lot.