JQL: Some points to add in documentation of JQL

Some points need to be added for JQL documentation:

• pid is not supported as alias for project right now. Can be confirmed with dev team whether it will supported in future?
• User can't use e-mail id as search in assignee and reporter field. We need to remove this from doc.....Can be confirmed with dev team whether it will supported in future?
• We should mention the usage of brackets for defining the precedence of operators. This is really useful.
• workratio need to be mention in documentation.
• parent
• cascadingselect(val,val)
• unreleasedversion()