Allow user to use default package names in from wsdl scenarios

-create ws or ws client from attached WSDL

=> fails due to:
Failed to Generate Web Service code, please check the log for more details
org.eclipse.core.runtime.CoreException: parsing WSDL...

[ERROR] Two declarations cause a collision in the ObjectFactory class.
line 227 of http://schemas.xmlsoap.org/soap/encoding/

[ERROR] (Related to above error) This is the other declaration.
line 365 of file:/space/workspace-jboss/jbosstools-trunk/ws/tests/org.jboss.tools.ws.ui.test/resources/interfax.wsdl

[ERROR] Two declarations cause a collision in the ObjectFactory class.
line 444 of http://schemas.xmlsoap.org/soap/encoding/

[ERROR] (Related to above error) This is the other declaration.
line 363 of file:/space/workspace-jboss/jbosstools-trunk/ws/tests/org.jboss.tools.ws.ui.test/resources/interfax.wsdl

[ERROR] Two declarations cause a collision in the ObjectFactory class.
line 366 of file:/space/workspace-jboss/jbosstools-trunk/ws/tests/org.jboss.tools.ws.ui.test/resources/interfax.wsdl

[ERROR] (Related to above error) This is the other declaration.
line 453 of http://schemas.xmlsoap.org/soap/encoding/

[ERROR] Two declarations cause a collision in the ObjectFactory class.
line 364 of file:/space/workspace-jboss/jbosstools-trunk/ws/tests/org.jboss.tools.ws.ui.test/resources/interfax.wsdl

[ERROR] (Related to above error) This is the other declaration.
line 291 of http://schemas.xmlsoap.org/soap/encoding/

Workaround: use binding files/inline wsdl customizations to resolve conflicts or switch to command line and use "wsconsume -k interfax.wsdl" (note ommited '-p' argument) to let the tool generate default packages (according to spec) from target namespaces defined in WSDL

problem here is that we, in ws from wsdl and ws client wizards/scenarios, are forcing user to set a package name for generated classes but setting/using package name is not mandatory for under-lied tools (default behaviour is to map namespaces defined in WSDL/XSD to java package names - defined by spec), so we should relax this constraint