title: Is the query parameter waitForSync supported in all modification APIs in ArangoDB?
body: <p>For example, in the documentation of the API for adding a vertex collection
  <a href="https://docs.arangodb.com/3.0/HTTP/Gharial/Management.html#add-vertex-collection" rel="nofollow">https://docs.arangodb.com/3.0/HTTP/Gharial/Management.html#add-vertex-collection</a>
  there is a mention about waitForSync in "Return Codes" section.</p>
  
  <ul>
  <li>201: Returned if the edge collection could be added successfully and
  waitForSync is true.</li>
  <li>202: Returned if the edge collection could be    added successfully
  and waitForSync is false.</li>
  </ul>
  
  <p>However there is no "Query Parameter" section for this API.</p>
  
  <p>Actually I tried to add waitForSync=true for this API, but I got result code 202, not 201 which I expected.
  <a href="https://github.com/hnakamur/arangogo/blob/e6906759bead9857424782b4ab294ad4992bf1a9/cmd/example2/main.go#L103-L109" rel="nofollow">https://github.com/hnakamur/arangogo/blob/e6906759bead9857424782b4ab294ad4992bf1a9/cmd/example2/main.go#L103-L109</a></p>