WebSearch: new Add-to-Search Interface

* New search box interface that contains both simple search and advanced
  search (javascript dependent).  (addresses #622)

* Replaces the 3-line advanced search, with only 1-line add-to-search,
  with the possibility of adding patterns to the current search pattern.

* Ammends regression tests to take into account a third search
  interface.

* Moves the config variables `CFG_WEBSEARCH_ENABLED_SEARCH_INTERFACES`
  and `CFG_WEBSEARCH_DEFAULT_SEARCH_INTERFACES` from the `inveniocfg.py`
  to `search_engine_config.py` and `invenio.config`
  respectively.  (closes #271)  (PR #1738)

Signed-off-by: Ludmila Marian <ludmila.marian@gmail.com>
Co-authored-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
webcoll: fix for "--language" option

* Fixes cache re-creation for a subset of all available
  languages.  (closes #1399) (PR #2219)

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
BibMerge: `onclickSubmitButton` missing comma fix

* Fixes missing comma in `onclickSubmitButton`.  (PR #2230)

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
WebSearch: fix for record numbering in pagination

* Adds optional `nb_found` argument to `print_records` allowing for a
  different list of records to be printed and number of records found,
  when we are only printing a subset of a total number of records
  found.  (closes #1762) (PR #1763)

Signed-off-by: Nikolaos Kasioumis <nikolaos.kasioumis@cern.ch>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
WebSubmit: link to successfully created record

* Shows link to new record if possible.  (closes #1641)

Signed-off-by: Patrick Glauner <patrick.oliver.glauner@cern.ch>
Tested-by: Tibor Simko <tibor.simko@cern.ch>
BibRank: fix of similar-to-recid result order

* Fixes order of results.  (addresses #1745) (PR #2236)

Signed-off-by: Patrick Glauner <patrick.oliver.glauner@cern.ch>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
SolrUtils: fix of similar-to-recid result order

* Fixes order of results.  (closes #1745) (PR #2236)

Signed-off-by: Patrick Glauner <patrick.oliver.glauner@cern.ch>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
docs: initial release of CONTRIBUTING guide

* Adds `CONTRIBUTING.rst` guide, taken from our old Trac wiki site,
  reusing the old content, updating it only slightly so far.
  (closes #2163)

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
Merge branch 'maint-1.0' into maint-1.1

* maint-1.0:
  docs: initial release of CONTRIBUTING guide

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
Merge branch 'maint-1.1'

* maint-1.1:
  docs: initial release of CONTRIBUTING guide

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
WebSearch: richer `/record` and `/search` API docs

* Enriches documentation about `/search` API with new sections
  describing XML API and JSON API, with notes and usage examples.
  (addresses #2303)

* Adds new "Record API" documentation describing `/record/` API, with
  notes and usage examples.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
filtering option for all pages
added simple matching comment count
upgrade script for new table cmtRECORDCOMMENT_bibdocfile
Added some more skeleton for the actual comment-bibdocfile association.
interface to associate comment with file roughly done, need to add logic for submitting the comment
Selection is available from the web interface and the
selected file is now saved as an associated file to
the new comment in the database
filtering by file is now implemented, combined with text query in comments, better styling is still required.
minor fixes
file filters are trasfered to subsequent searches