The app version of an operator package is taken into account using operations that apply to packages. E.g., when installing a package, a user is able to provide a specific app version to install. To further distinguish app version and operator version, the 'version' field in operator packages and the package index has been renamed to 'operatorVersion'.
Package version resolution has been updated to take the app version into account; operator packages are first sorted by app version, then sorted by operator version. Furthermore, the app version is added to the package tarball name to avoid conflicts.

Co-Authored-By: Aleksey Dukhovniy <adukhovniy@mesosphere.io>

Signed-off-by: Ken Sipe <kensipe@gmail.com>