BUG8446, Follow up: Refactor to clean up bad practice

- A number of issues were highlighted whilst writing sensible unit tests
  for this module.
  - Removed unnessesary call to context->new();
  - Global variables are BAD!
  - Croaking is a wimps way out, we should handle errors early and
    properly.
BUG12026: Adds auto-provisioning to shibboleth

- Adds the option to map shibboleth attributes to koha user columns
  and allows mapping to auto create non-existant users

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
BUG 12026, Follow up: Added Documentation

BUG 12026, Follow up: Updated to work with match point selection

- The base bug that this patch enhances has added the ability to choose
  your match point in the configuration file. This patch adds code to
  take that change into account.
BUG 12027: Added shibboleth authentication to the staff client

- This patch adds shibboleth authentication to the staff client.
- Depending upon how your url structure works, you may or may not need a
  second native shibboleth service provider profile configured for this
  to work.

http://bugs.koha-community.org/show_bug.cgi?id=12026
BUG 8446, followup: Add Unit Tests