Fix usage of Automation aliases

The use of aliases is not working.

For instance, using the old Document.Query operation, which is an alias of the new Repository.Query operation, fails:

• from Nuxeo Shell

  > Document.Query  -query "select * from File"
  Unknown command: Document.Query
  

• from a curl command

  curl -X POST 'http://demo.nuxeo.com/nuxeo/site/automation/Document.Query' -u Administrator:Administrator -H 'Nuxeo-Transaction-Timeout: 3' -H 'X-NXproperties: *' -H 'X-NXRepository: default' -H 'X-NXVoidOperation: false' -d '{"params":{"query":"select * from File","language":"NXQL","sortOrder":"ASC"},"context":{}}'
  

  it raises a NPE

  Apr 19, 2016 2:44:48 PM com.sun.jersey.spi.container.servlet.WebComponent filterFormParameters
  WARNING: A servlet request, to the URI http://nereid2:8080/nuxeo/site/automation/Document.Query, contains form parameters in the request body but the request body has been consumed by the servlet or a servlet filter accessing the request parameters. Only resource methods using @FormParam will work as expected. Resource methods consuming the request body by other means will not work as expected.
   {}14:44:48,564 WARN  [WebEngineExceptionMapper] Exception in JAX-RS processing
   {{PathInfo,/automation/Document.Query}{RemoteAddr,10.213.3.49}{RequestURL,http://localhost:8080/nuxeo/site/automation/Document.Query}{ServletPath,/site}{UserPrincipal,Administrator}}java.lang.NullPointerException
  	at org.nuxeo.ecm.automation.server.jaxrs.OperationResource.execute(OperationResource.java:50)
  	at org.nuxeo.ecm.automation.server.jaxrs.ExecutableResource.doPost(ExecutableResource.java:61)
  	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  	at java.lang.reflect.Method.invoke(Method.java:497)
  	at com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
  
  

But it works when pasting the URL http://localhost:8080/nuxeo/site/automation/Document.Query in a browser

{
  "id" : "Repository.Query",
  "aliases" : [ "Document.Query" ],
  "label" : "Query",
  "category" : "Fetch",
  "requires" : null,
...