Add "spec" keyword for pipes_dict
Add new keyword "parameter" for show_runs pipe using "spec" new keyword
Add validator for new pipe format
Add empty dict into old style pipe definition
Adapt new format in dpmanip
Change pipe format in execute
Remove spec keyword
Merge pull request #142 from termoshtt/pipe_nargs

Pipe nargs
Add filter by path pipe.
Update zsh-completion.
Minor change.