Feature: add service.tib.eu/ts4tib as OLS endpoint

[sneumann]

Hi,
https://service.tib.eu/ts4tib/ is a Terminology Service (TS) building on the OLS software system, including an API that is OLS compatible.
While OLS is mainly targeting the life-sciences, the ts4tib provides a Terminologies for many more disciplines.

We'd like to submit a PR that will add the TS to OntoMaton.
TS API Documentation: https://service.tib.eu/ts4tib/swagger-ui.html

Yours,
Steffen

[sneumann]

This will need

• Addition to the documentation:

  OntoMaton/Ontomaton-terms.md

  Line 14 in c7fe0b5

  <li><a href="https://www.ebi.ac.uk/ols/docs/api" rel="nofollow">EMBL-EBI Ontology Lookup Service</a></li>

• Addition to the README:

  OntoMaton/README.md

  Line 31 in c7fe0b5

  - we extended the ontology search functionality to support REST services from the <a href="http://lov.okfn.org/">Linked Open Vocabularies</a> and the <a href="https://www.ebi.ac.uk/ols/">EBI Ontology Lookup Service</a>, thus now allowing ontology term searches over three separate services.

• Maybe some new constants:

  OntoMaton/Utils.gs

  Line 34 in c7fe0b5

  // constants

• Maybe new settings:

  OntoMaton/Settings.gs

  Line 178 in c7fe0b5

  function getOLSOntologies() {

• Maybe add TS search:

  OntoMaton/OntologySearch.gs

  Line 225 in c7fe0b5

  function searchOLS(term) {

• ... Some more places ...