Add subject assessor information to Xnatinfo output

[duettwe]

dax issue #533

This adds subject level assessor counts to Xnatinfo. It is empty when there are none.

Tested using HeckersESOP (has 258 subject assessors) and DARBY (has none).

Let me know if we need any more changes/updates or if something isn't quite right.

[baxpr]

Works for me! Let's add XnatSwitchProcessStatus updates here too, if that doesn't take too long.

[duettwe]

XnatSwitchProcessStatus isn't quite there yet. Would not merge this yet.

[duettwe]

(dax) [duettw@gw02 ~]$ ./XnatSwitchProcessStatus-test --select HeckersESOP-x-2-000982-23-x-fs810-long2_v2-x-cb92d4e0 -s NEED_TO_RUN --sublev
################################################################
#                   XnatSwitchProcessStatus-test               #
#                                                              #
# Developed by the MASI Lab Vanderbilt University, TN, USA.    #
# If issues, please start a thread here:                       #
# https://groups.google.com/forum/#!forum/vuiis-cci            #
# Usage:                                                       #
#     Change assessor job/quality control status.              #
# Examples:                                                    #
#     Check the help for examples by running --help            #
################################################################

----------------------------------------------------------------
Arguments:
  select          -> ...-2-000982-23-x-fs810-long2_v2-x-cb92d4e0
  status          -> NEED_TO_RUN                                
  sublev          -> on                                         
----------------------------------------------------------------

================================================================
INFO: connection to xnat <https://xnat.vanderbilt.edu/xnat>:
INFO: Switching assessors status:
  + Process 1/1 : HeckersESOP-x-2-000982-23-x-fs810-long2_v2-x-cb92d4e0
   - Job Status on Assessor HeckersESOP-x-2-000982-23-x-fs810-long2_v2-x-cb92d4e0 changed to NEED_TO_RUN
============== XnatSwitchProcessStatus-test DONE ===============

[duettwe]

This works, but there are a few caveats:

1. Only works with --sublev flag
2. Only works with --select (ie - not for entire projects; one at a time) - Actually, not entirely sure with this. I'm assuming it doesn't - Too afraid to test.
3. DOESN'T work with -d (Not sure if this is needed???)

[baxpr]

Niiiiice! Next priority would be to have it work with --rerundiskq flag to delete and reset all of a type with JOB_FAILED status.