hg: jdk9/dev/langtools: 8081845: JShell: Need way to refresh relative to external state

[robert.field at oracle.com]

Changeset: a3633a34baa8
Author:    rfield
Date:      2016-01-11 08:41 -0800
URL:       http://hg.openjdk.java.net/jdk9/dev/langtools/rev/a3633a34baa8

8081845: JShell: Need way to refresh relative to external state
Summary: Add the ability to record and replay relevant parts of history
Reviewed-by: jlahoda

! src/jdk.jshell/share/classes/jdk/internal/jshell/tool/JShellTool.java
+ test/jdk/jshell/ToolReloadTest.java