Fix for JERSEY-1833: Failing to call WadlGenerator#init results in NPE in ant-wadl-task
 - added reproducible test case that simulates ANT script invocation
 - fixed WadlBuilder, so that the default generator gets properly initialized, updated javadocs

Change-Id: I9dadf92bfba8d8da640aa7410b6f62aff38240cf
Signed-off-by: Jakub Podlesak <jakub.podlesak@oracle.com>
Merge "Fix for JERSEY-1833: Failing to call WadlGenerator#init results in NPE in ant-wadl-task  - added reproducible test case that simulates ANT script invocation  - fixed WadlBuilder, so that the default generator gets properly initialized, updated javadocs"