hg: kulla/dev/langtools: Add code comments

[robert.field at oracle.com]

Changeset: 0da5c74be1b6
Author:    rfield
Date:      2015-08-20 13:21 -0700
URL:       http://hg.openjdk.java.net/kulla/dev/langtools/rev/0da5c74be1b6

Add code comments

! src/jdk.jshell/share/classes/jdk/jshell/Key.java
! src/jdk.jshell/share/classes/jdk/jshell/KeyMap.java
! src/jdk.jshell/share/classes/jdk/jshell/MaskCommentsAndModifiers.java
! src/jdk.jshell/share/classes/jdk/jshell/MemoryFileManager.java