8080352: jshell tool: Error message for using "package" should be more descriptive than "Failed"
Reviewed-by: jlahoda

8143964: JShell API: convert query responses to Stream instead of List
Reviewed-by: psandoz, shinyafox

8134254: JShell API/tool: REPL for Java into JDK9
Summary: Adding the implementation of the jshell (read-eval-print-loop) tool.
Reviewed-by: briangoetz, mcimadamore, psandoz, forax
Contributed-by: robert.field@oracle.com, bitterfoxc@gmail.com, jan.lahoda@oracle.com