OAIHarvest: holding-pen UI bugfixes

* Adds new JS scripts (jQuery UI accordion) in order to fix
  the currently broken UI interface. (closes #1041)

* Changes some functions in getHoldingPenData and adds a new
  function perform_request_gethpall to adopt to the updated UI.

* Adds some new CSS classes.

* Fixes some kwalitee warnings.

Tested-by: Tibor Simko <tibor.simko@cern.ch>