provide super easy logging for pipeline authors

[nsheff]

the PipelineManager object should provide easily user-tweakable verbosity settings.

Not sure if it should make use of logmuse or just logging. but i wwant to be able to write:

pm.debug("blahblah")
pm.warn("blahblah")
pm.detail("blahbalh")

[vreuter]

Can you spec out the API you want?

[nsheff]

I don't have a strong opinion. Whatever you suggest and would like to use for your pipelines would be fine with me.