Allow __process to accept lists as arguments
Allow __process to accept lists as arguments

This allows 'plugins' (and other functions) to have a more natural API,
e.g.:

- girder:
  username: "adming"
  password: "letmein"
  plugins:
    - foo
    - bar

Rather than:

- girder:
  username: "adming"
  password: "letmein"
  plugins:
    plugins:
      - foo
      - bar

Note however,  if you want to pass optional arguments to a function you
MUST use the 'dict' style arguments.  For instance:

- girder:
  username: "adming"
  password: "letmein"
  get:
    path: "user"

Could also be expressed:

- girder:
  username: "adming"
  password: "letmein"
  get:
    - "user"

with the current commit. However, if you wanted to pass paramaters you
would HAVE TO use the 'dict' style form:

- girder:
  username: "adming"
  password: "letmein"
  get:
    path: "user"
    parameters:
      id: "562b98be0640fd36f027b345"

opadron/girder,essamjoubori/girder,manthey/girder,sutartmelson/girder,opadron/girder,RafaelPalomar/girder,girder/girder,Xarthisius/girder,jbeezley/girder,kotfic/girder,Xarthisius/girder,Kitware/girder,msmolens/girder,essamjoubori/girder,kotfic/girder,Kitware/girder,msmolens/girder,adsorensen/girder,RafaelPalomar/girder,kotfic/girder,Xarthisius/girder,data-exp-lab/girder,manthey/girder,essamjoubori/girder,adsorensen/girder,opadron/girder,Kitware/girder,sutartmelson/girder,girder/girder,RafaelPalomar/girder,jbeezley/girder,data-exp-lab/girder,salamb/girder,Xarthisius/girder,RafaelPalomar/girder,msmolens/girder,Kitware/girder,data-exp-lab/girder,salamb/girder,Xarthisius/girder,opadron/girder,data-exp-lab/girder,salamb/girder,msmolens/girder,sutartmelson/girder,kotfic/girder,sutartmelson/girder,kotfic/girder,jbeezley/girder,girder/girder,salamb/girder,essamjoubori/girder,manthey/girder,data-exp-lab/girder,sutartmelson/girder,RafaelPalomar/girder,adsorensen/girder,msmolens/girder,essamjoubori/girder,adsorensen/girder,opadron/girder,girder/girder,manthey/girder,jbeezley/girder,salamb/girder,adsorensen/girder