Move WSDL files location to 'src/main/wsdl/'.

To comply with conventions similar to the ones used by the Apache Axis
Maven module, the WSDL files location is changed from the project base
directory folder to 'src/main/wsdl'. It also makes IDEs display the WSDL
files as other sources instead of not displaying them at all.
Number license conditions in the templates.

Aesthetic changes consisting in adding numbers to the list of
conditions (clauses) in the license headers present in the
templates to look similar to the rest of the sources.