updating the parsets for the target and the config scripts to include PIPELINE_STEP instead of PIPELINE

Rewriting the stager_access decorator to use @wrapper so that all the wrapped functions are documented by sphinx

Creting a token dictionary can now use id_prefix to switch from SB### to AB###. This allows to dynamically name the token IDs.

Adding a dropout exception handling for the case where gfal doesn't exist to allow sphinx to make docs even without gfal in env

 adding state_all which processes a list of srm:// or gsiftp:// links and returns their status, and the percentage staged using the gfal2 interface