[SQLLINE-221] Now require Java 8 or higher

Document twitter account.

README.md

@@ -99,7 +99,7 @@ Use the following definition to use `sqlline` in your maven project:
 Prerequisites:
 
 * Maven 3.2.5 or higher
-* Java 1.6 or higher (10 preferred)
+* Java 8 or higher (10 preferred)
 
 Check out and build:
 
@@ -133,6 +133,7 @@ mvn package
   <a href="mailto:sqlline-dev@googlegroups.com">sqlline-dev at googlegroups.com</a>
   (<a href="https://groups.google.com/group/sqlline-dev/topics">archive</a>,
   <a href="https://groups.google.com/group/sqlline-dev/subscribe">subscribe</a>)
+* Twitter: [@SQLLineShell](https://twitter.com/SQLLineShell)
 * [Issues](https://github.com/julianhyde/sqlline/issues)
 * [Release notes and history](HISTORY.md)
 * [HOWTO](HOWTO.md)

docs/manual.html

@@ -178,7 +178,7 @@
       <code class="filename">sqlplus</code> for Oracle, <code class="filename">mysql</code>
       for MySQL, and <code class="filename">isql</code> for Sybase/SQL Server.
       Since it is pure Java, it is platform independent, and will
-      run on any platform that can run Java 1.6 or higher.
+      run on any platform that can run Java 8 or higher.
       </p>
     </div>
 
@@ -219,7 +219,7 @@
           </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
             <span class="trademark">Java</span>&#8482; Virtual Machine -
             SQLLine is a pure
-            java program, and requires Java version 1.6 or higher
+            java program, and requires Java version 8 or higher
             in order to run. The latest JVM can be downloaded from
             <a class="ulink" href="http://java.sun.com" target="_top">http://java.sun.com</a>.
             </p></li><li class="listitem"><p>

src/docbkx/manual.xml

@@ -32,7 +32,7 @@
       <filename>sqlplus</filename> for Oracle, <filename>mysql</filename>
       for MySQL, and <filename>isql</filename> for Sybase/SQL Server.
       Since it is pure Java, it is platform independent, and will
-      run on any platform that can run Java 1.6 or higher.
+      run on any platform that can run Java 8 or higher.
       </para>
     </chapter>
 
@@ -74,7 +74,7 @@
             <listitem><para>
             <trademark>Java</trademark> Virtual Machine -
             SQLLine is a pure
-            java program, and requires Java version 1.6 or higher
+            java program, and requires Java version 8 or higher
             in order to run. The latest JVM can be downloaded from
             <ulink url="http://java.sun.com"/>.
             </para></listitem>