Add documentation for all SqoopTool implementations.
Add database compatibility notes.
Separate user guide from the develpment guide.
From: Aaron Kimball <aaron@cloudera.com>
git-svn-id: https://svn.apache.org/repos/asf/incubator/sqoop/trunk@1149902 13f79535-47bb-0310-9956-ffa450edef68