Tests that no 
         err:XS0002 is raised, if steps with same name are
  in different scopes.
Test ab-unique-step-names-001.xml is expected to pass.
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
   <p:output port="result">
   <p:group>
      <p:identity name="step">
         <p:with-input>
            <doc/>
         </p:with-input>
      </p:identity>
   </p:group>
   <p:group>
      <p:identity name="step">
   </p:group>
</p:declare-step>
<s:schema xmlns:s="http://purl.oclc.org/dsdl/schematron" queryBinding="xslt2">
   <s:pattern>
      <s:rule context="/">
         <s:assert test="doc">The pipeline root is not doc.</s:assert>
      </s:rule>
   </s:pattern>
</s:schema>
Added attribute 'queryBinding' to schematron's schema.
Initial commit