UI: adds space on "About" page
records: shows given disclaimer if exists
config: updating the SITE_NAME displayed

* (closes #701)
records: corrects text in pop-up box

* (addresses #685)
README: clearer wording about this repository

* Clarifies that this is just a source code repository, and that the
  CERN Open Data Portal is located elsewhere.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>