WebSearch: performace improvement

* Improves the performace of the collection children cache
  by minimizing the number of database calls

Signed-off-by: Ludmila Marian <ludmila.marian@gmail.com>
WebColl: fix for "--language" option

* Fixes cache re-creation for a subset of all available
  languages.  (closes #1399)
WebSearch: fix for snippet highlighting

* Highlights terms that are only searched in fulltext.

Signed-off-by: Patrick Glauner <patrick.oliver.glauner@cern.ch>
WebSubmit: new output of link to successfully created record

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

Signed-off-by: Patrick Glauner <patrick.oliver.glauner@cern.ch>
Merge branch 'prod' of github.com:CERNDocumentServer/cds-ops into prod
WebLinkback: faster email notification

 * Improves database layer to send email notification faster

 * Extends regression tests for this improvement

 * Applies minor clean-up
WebLinkback: faster deletion of linkbacks on blacklist

 * Avoids redundant creations of blacklist