DS-1483 Generate citation_pdf_url in more cases

Google Scholar uses the citation_pdf_url header tag on item pages to determine
which of an item's bitstreams to link to (if any). Standard DSpace behaviour is
to include this link only if the item has exactly one bitstream in the ORIGINAL
bundle and if this item is of type application/pdf. The desired behaviour for
the LCoNZ IRRs is this:
 - if the item has only one bitstream in the ORIGINAL bundle, link to this one
 - if the item has a primary bitstream in the ORIGINAL bundle, link to this one
   (regardless of how many bitstreams there are in total in the ORIGINAL bundle).
Additionally, the bitstream link should only appear when the bitstream selected
according to the rules above is publicly visible.
The mimetype of the bitstream is not taken into account, as per Google Scholar
feedback that this is no longer as important to them.
Fix the bug DS-1780

The batch import would go into an infinite loop when loading from a
pubmed, arxiv or crossref XML file. This was due to the fact that the
respective data loaders open the file each time getRecords() is called
coupled with the complicated logic of TransformationEngine.

The bug was fixed by checking if offset is greater than zero in
getRecords(DataLoadingSpec) (which is equivalent to the condition that
the file has already been read) and if so the method returns an empty
RecordSet signaling the TransformationEngine that the input has ended.
Minimal redesing to uniform to the xmlui, add datepicker js on embargo date, limit policy name field to maxlength=30
Add support in review page for access settings
jspui bootstrap layout minor tweak
Move code into more appropriate jsp, manage submission when embargo feature is off
[DS-1621] First stab at configurable search for Item mapper
[DS-1788] Update command names and descriptions
DS-1774 move hardcoded text to i18n
Move the retrieve resource policies and other info to the servlet
Change from submission attribute to request attribute
Change way to retrieve data
Changed way to retrieve object from submission map to request attribute, remove code to show number of policies setting in the case of simple embargo form
DS-1676 Impossible to cancel/save or go back in the upload step with upload progress bar enabled
Add missing image for sherpa/romeo
Fix misuse of previous button to avoid file upload when required (noted by lap82)
Merge pull request #402 from abollini/DS-1676-simply

[DS-1676] Upload file step wrong navigation feel
Merge pull request #400 from DSpace/DS-1774

DS-1774 move hardcoded text to i18n
Add message embargo in review section for bitstream
Merge pull request #395 from lap82/DS-1793-DS-1794

[DS-1793][DS-1794] Redesing embargo advanced form