New API methods to query Lookup for changes.

src/application.wadl

src/generate-client-methods.py

src/java/uk/ac/cam/ucs/ibis/methods/GroupMethods.java

src/java/uk/ac/cam/ucs/ibis/methods/IbisMethods.java

src/java/uk/ac/cam/ucs/ibis/methods/InstitutionMethods.java

src/java/uk/ac/cam/ucs/ibis/methods/PersonMethods.java

src/php/ibisclient/methods/GroupMethods.php

src/php/ibisclient/methods/IbisMethods.php

src/php/ibisclient/methods/InstitutionMethods.php

src/php/ibisclient/methods/PersonMethods.php

src/php/test/UnitTests.php

src/python/ibisclient/methods.py

src/python/test/unittests.py

src/python3/ibisclient/methods.py

src/python3/test/unittests.py