pipeline: remove lookup function pointer

For now we are content to tie the pipeline implementation to OVSDriver.
remove pipeline utest

It wasnt't doing anything, and linking with OVSDriver is complicated.
pipeline: implement registration
factor out pipeline_standard into its own module
pipeline: integrate with Indigo pipeline interfaces
ivs: support setting pipeline name from the command line

The argument is optional, so the syntax is "--pipeline=standard-1.3".