templates: CMS Physics Objects link fix

* Fixes links to CMS Physics Objects page.
  (addresses #153) (addresses #198)

* In addition, removes `^L` and `^K` characters in the text.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
templates: one more link to Physics Objects

* Adds one more link to CMS Physics Objects.
  (addresses #153) (addresses #198)

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
base: JSON data model fix for external URLs

* Fixes JSON data model for external URLs (`8564`).

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
UI: "disclaimer" text changed

* (closes #139)