title: jira zephyr database scheme
body: <p>I need to collect information about test cases and test execution results directly from JIRA DB (Oracle 11g) with Zephyr plugin but I cannot find where exactly that information is stored by the plugin.
  Can someone share typical DB schema for Zephyr plugin?
  For now I only could find that testcases are the same as jira's issues and stored together in jiraissue table and information about executions are somewhere like 'AO_%' tables.</p>