Changes to OAI implementation to fix validation issues.

Fixes include:-

  - adminEmail example now uses correct form
  - Delimiter reverted to ":"
  - OAI code overridden to return identifiers as "oai:hull.ac.uk:hull:123" instead of "oai:hull.ac.uk/hull:123" (which failed validation)
  - Temporarily removed <setDescription> tag from ListSets - Will implement oai_dc within setDescription at a later date

Changes to oai to pass validation

Removed setDescription element from the "ListSets" response.
Added valid e-mail examples

comments added to overrides