Renamed doc directory to users_guide

users_guide/Makefile

users_guide/book.xml

users_guide/bookinfo.xml

users_guide/build.xml

users_guide/changes.xml

users_guide/clipboardtut.xml

users_guide/custom-fo.xsl

users_guide/custom-html.xsl

users_guide/differences.xml

users_guide/dragdroptut.xml

users_guide/events.xml

users_guide/examples.xml

users_guide/gems.xml

users_guide/goals.xml

users_guide/images/babelfish.png

users_guide/images/browser.png

users_guide/images/button.png

users_guide/images/call-chain-example.dia

users_guide/images/call-chain-example.png

users_guide/images/colordialog.png