Big tool rename.

As promised, this is the "big tool rename" patch.  The primary differences
since 0.99.6 are:

  (1) git-*-script are no more.  The commands installed do not
      have any such suffix so users do not have to remember if
      something is implemented as a shell script or not.

  (2) Many command names with 'cache' in them are renamed with
      'index' if that is what they mean.

There are backward compatibility symblic links so that you and
Porcelains can keep using the old names, but the backward
compatibility support  is expected to be removed in the near
future.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-hash-object.txt

@@ -17,7 +17,7 @@ Computes the object ID value for an object with specified type
 with the contents of the named file (which can be outside of the
 work tree), and optionally writes the resulting object into the
 object database.  Reports its object ID to its standard output.
-This is used by "git-cvsimport-script" to update the cache
+This is used by "git-cvsimport" to update the cache
 without modifying files in the work tree.  When <type> is not
 specified, it defaults to "blob".