8171130: jshell tool: /edit adds empty statement to brace terminated snippet
8173007: JShell Tests: ToolFormatTest takes too long
Reviewed-by: jlahoda

8169828: jdk/jshell/ExternalEditorTest.java testStatementMush() fails frequently on all platform
8170015: jshell tool: /help output looks terrible on a 100 column wide terminal
8170368: jshell tool: post setting not properly applied, line-ends not prefixed correctly
Reviewed-by: jlahoda

8143006: jshell tool: /edit doesn't process each line as same as inputs for jshell
8163816: JShell tests: jdk/jshell/ExternalEditorTest.java -- unexpected results EditorTestBase.testEditClass1() and .testEditMethod1()
Reviewed-by: jlahoda

8163840: jshell tool: provide way to display configuration settings
Reviewed-by: jlahoda

8160089: jshell tool: use new double-dash long-form command-line options
Reviewed-by: jlahoda

8163817: JShell tests: disable minor failing editor tool cases: 8161276, 8163816, 8159229
Reviewed-by: jlahoda, psandoz, darcy

8080843: JShell tool: invalid key error occurs when external editor is used
Reviewed-by: vromero

8143955: JShell tool (UX): Output structure
8143956: JShell tool (UX): default prompts
Reviewed-by: jlahoda

8148316: jshell tool: Configurable output format
8148317: jshell tool: unify commands into /set
8149524: JShell: CompletenessAnalysis fails on class Case<E1 extends Enum<E1>, E2 extends Enum<E2>, E3 extends Enum<E3>> {}
Reviewed-by: jlahoda

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