use auto keyword to declare iterator variables where possible * dialog.cc, files-dock-widget.cc, history-dock-widget.cc, file-editor.cc, octave-qt-link.cc, call-stack.cc, debug.cc, dynamic-ld.cc, fcn-info.cc, fcn-info.h, genprops.awk, graphics.cc, gtk-manager.cc, gtk-manager.h, hook-fcn.h, load-path.cc, load-save.cc, ls-mat5.cc, mex.cc, oct-map.cc, oct-stream.cc, octave-link.cc, regexp.cc, symscope.h, symtab.h, txt-eng.h, url-handle-manager.cc, variables.cc, ov-base.cc, ov-class.cc, ov-classdef.cc, ov-fcn-handle.cc, ov-java.cc, ov-struct.cc, bp-table.cc, jit-ir.cc, jit-typeinfo.cc, pt-arg-list.cc, pt-arg-list.h, pt-array-list.cc, pt-check.cc, pt-classdef.cc, pt-decl.h, pt-eval.cc, pt-idx.cc, pt-jit.cc, pt-misc.cc, pt-pr-code.cc, pt-select.h, pt-stmt.h, caseless-str.h, lo-regexp.cc: Use auto keyword to declare iterator variables where possible. Style fixes.

--- a/libinterp/parse-tree/pt-decl.h	Wed May 02 00:30:00 2018 -0400
+++ b/libinterp/parse-tree/pt-decl.h	Wed May 02 01:36:20 2018 -0400
@@ -137,7 +137,7 @@
     {
       while (! empty ())
         {
-          iterator p = begin ();
+          auto p = begin ();
           delete *p;
           erase (p);
         }