profile format changes

[nsheff]

Related to: https://github.com/databio/pypiper/issues/142

A few suggestions for improving the profile report:

• [x] move the target to the last column, because it's so long, making it easy for things to line up in the earler colums
• [x] make lock column relative to outfolder?
• [x] add unique key (see https://github.com/databio/pypiper/issues/142)
• [x] add process number (would allow tying to specific pipeline run)
• [x] use different process names for piped processes. right now piped processes are printed with the same process name, which seems strange (it's the parent process).