Remove Workflow content from 6.2 Dev Guide until Kaleo plugin available for Portal 6.2 on Studio 2.0

Hi Rich,

I removed the chapter file for the time being. I replaced the numbered chapter references (e.g., "see Chapter 7") with links that use the section/chapter titles. 

I didn't update the figure numbers. I'd rather wait until the JSF chapter will be inserted to avoid any unnecessary figure number updates. :-)

https://issues.liferay.com/browse/LRDOCS-894

This is ready for master. Thank you.