Improve UX for I/O Variables mapping

I miss some capabilities on the current Data Type field when using Process Variables and I/O Data Mapping.

For instance:

1) It should include in the default combo some common Java Data Types used in almost every real Process, like: java.util.List and com.jbpm.document.Document
2) I should allow typing a custom data type with just double-click or just at first key-stroke on focus
3) have auto-completion for data types/classes included as dependency in the project
3) It would be nice to have a way to easily see the full data type name on hovering the mouse on it or auto-expand the field... Today it is too tiny....
4) remember Custom Types already used/added with no need to enter again and again in every task Data mapping I/O