WebStyle: legacy publisher support for Flask

* Supports func:`mp_legacy_publisher` while serving static files through
  Flask application.

* Registers exception and informs admin on any top level error.

Tested-by: Tibor Simko <tibor.simko@cern.ch>
WebSearch: fix default sort order

* Fixes sort order of search results and collection reclist.

* Adds limit for number of records in '/collection' pages.

Reported-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Tested-by: Tibor Simko <tibor.simko@cern.ch>