doc: Shorten some long subsection names in Manual. Remove excess spaces from ends of @menu definitions. * doc/interpreter/arith.txi, doc/interpreter/basics.txi, doc/interpreter/bugs.txi, doc/interpreter/container.txi, doc/interpreter/data.txi, doc/interpreter/diagperm.txi, doc/interpreter/diffeq.txi, doc/interpreter/emacs.txi, doc/interpreter/expr.txi, doc/interpreter/external.txi, doc/interpreter/func.txi, doc/interpreter/grammar.txi, doc/interpreter/gui.txi, doc/interpreter/install.txi, doc/interpreter/intro.txi, doc/interpreter/io.txi, doc/interpreter/java.txi, doc/interpreter/linalg.txi, doc/interpreter/matrix.txi, doc/interpreter/nonlin.txi, doc/interpreter/numbers.txi, doc/interpreter/octave.texi, doc/interpreter/optim.txi, doc/interpreter/plot.txi, doc/interpreter/preface.txi, doc/interpreter/quad.txi, doc/interpreter/sparse.txi, doc/interpreter/stats.txi, doc/interpreter/stmt.txi, doc/interpreter/strings.txi, doc/interpreter/system.txi, doc/interpreter/var.txi: Shorten some long subsection names in Manual. Remove excess spaces from ends of @menu definitions.

--- a/doc/interpreter/var.txi	Fri Aug 02 15:16:48 2013 -0400
+++ b/doc/interpreter/var.txi	Fri Aug 02 13:52:39 2013 -0700
@@ -72,9 +72,9 @@
 @DOCSTRING(namelengthmax)
 
 @menu
-* Global Variables::            
-* Persistent Variables::        
-* Status of Variables::         
+* Global Variables::
+* Persistent Variables::
+* Status of Variables::
 @end menu
 
 @node Global Variables