BibEdit: minor fixes

* If revision passed on get record is invalid, default to the
  current one

* Fixes message displayed to the user after reverting a record

* Disable delete button after deleting a field

* Adds patch to the bibauthorid_name_utils that fixes the
  uppercase letter after accented letter. It's a temporary fix
  that uses regular expressions. Used in crossref import.

* Adds warning when browser blocks popups
BibEdit: tab switch between fields

* Jumps between field content with tab and backwards with
  shift + tab
BibEdit: better holdingpen integration

* Adds link in HoldingPen admin interface that redirects
  to bibedit and automatically shows all HoldingPen changes
  for a given record

* Automatically triggers the "apply HoldingPen change" when user clicks
  the "Apply changes" in Holding Pen admin area

* Adds parameter to createReq() function, that takes the deferred object

* Changes css classes of table cells in Holding Pen admin area

* Automatically triggers the "apply HoldingPen change"
  in BibEdit editor when user clicks the "Apply changes"
  in Holding Pen admin area

* Adds tooltips for icons

* Replaces ambiguous icons (fixes #87)

* Removes the two superfluous spaces in BibEdit editor
  between "Clone record" and "Manage templates icons"

Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>
BibEdit: custom errors for AJAX requests

* Default AJAX error now writes on browser console instead of
  showing alert.

* Several custom error examples.
BibEdit: merge record with template

* Checks field 980 to extract all collections of a record and if
  there is match with
  CFG_BIBEDIT_EXTEND_RECORD_WITH_COLLECTION_TEMPLATE extends the
  record with the given template
BibEdit: show/hide specific parts of the record

* Adds new box on the left panel that allows to select which parts
  of the record should be visible
BibEdit: remove extra holding pen call
BibEdit: update admin help page and shortcuts

* Disables some unused shortcuts

* Fixes some cases when pasting content

* Updates admin help accordingly
textutils: create function to show diff view

* New function to show diff of two records

* Use that function in BibEdit's comparison of revisions

Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>
Tested-by: Tibor Simko <tibor.simko@cern.ch>