Move keyring into Depends for repository since we do not apt-get update anyways
some notes + adding netselect into pre-depends of the neurodebian-repository
BF: Disable logic for demanding netselect (absent on ubuntus)

probably we could sophisticate it with all vendor-specific gizmos
http://raphaelhertzog.com/2010/09/27/different-dependencies-between-debian-and-ubuntu-but-common-source-package/
but it is just more reasonable to assume that netselect would eventually
come back