Remove references to org.eclipse.jgit.java7

The bundle org.eclipse.jgit.java7 was removed in 4.0.

Remove references to it from the README.md.

Remove reference to it from org.eclipse.jgit.test/.project, which
causes an error message when opening the project in Eclipse:

  Resource '/org.eclipse.jgit.java7' does not exist.

Change-Id: If0dbd562dcd60550bec3c0f793289474b7624bce
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

README.md

     All portions of JGit are covered by the EDL. Absolutely no GPL,
     LGPL or EPL contributions are accepted within this package.
 
-- org.eclipse.jgit.java7
-
-    Extensions for users of Java 7.
-
 - org.eclipse.jgit.ant
 
     Ant tasks based on JGit.
 
     Unit tests for org.eclipse.jgit
 
-- org.eclipse.jgit.java7.test
-
-    Unit tests for Java 7 specific features
-
 - org.eclipse.jgit.ant.test
 - org.eclipse.jgit.pgm.test
 - org.eclipse.jgit.http.test
 Warnings/Caveats
 ----------------
 
-- Native smbolic links are supported, but only if you are using Java 7
-  or newer and include the org.eclipse.jgit.java7 jar/bundle in the
-  classpath, provided the file system supports them. For Windows you
-  must have Windows Vista/Windows 2008 or newer, use a
-  non-administrator account and have the SeCreateSymbolicLinkPrivilege.
+- Native smbolic links are supported, provided the file system supports
+  them. For Windows you must have Windows Vista/Windows 2008 or newer,
+  use a non-administrator account and have the SeCreateSymbolicLinkPrivilege.
 
 - Only the timestamp of the index is used by jgit if the index is
   dirty.
     * Assorted set of command line utilities. Mostly for ad-hoc testing of jgit
       log, glog, fetch etc.
 
-- org.eclipse.jgit.java7/
-
-    * Support for symbolic links.
-
-    * Optimizations for reading file system attributes
-
 - org.eclipse.jgit.ant/
 
     * Ant tasks

org.eclipse.jgit.test/.project

 <projectDescription>
 	<name>org.eclipse.jgit.test</name>
 	<comment></comment>
-	<projects>
-		<project>org.eclipse.jgit.java7</project>
-	</projects>
 	<buildSpec>
 		<buildCommand>
 			<name>org.eclipse.jdt.core.javabuilder</name>