adds cpk endpoints datasources listing capability

this listing is provided through the exposed method listDataAccessTypes
of the CpkContentGenerator in JSON format, following the same
methodology of CDA.

added the following new dependencies:
 - jackson-core : http://search.maven.org/#browse%7C1722867014
 - jackson-annotations: http://search.maven.org/#browse%7C-799179585
 - jackson-databind: http://search.maven.org/#browse%7C808166526

please make sure that this dependencies are are available in the
classpath of the components that use the cpf-pentaho dependency.