use ' instead of ` in error messages, warnings and most comments * intro.txi, io.txi, munge-texi.cc, octave.texi, cmd-edit.cc, data-conv.cc, file-ops.cc, glob-match.h, kpse.cc, oct-env.cc, oct-locbuf.h, oct-md5.cc, oct-rand.cc, general/interp2.m, doc.m, get_first_help_sentence.m, help.m, print_usage.m, __additional_help_message__.m, type.m, unimplemented.m, which.m, cast.m, dir.m, license.m, mkoctfile.m, recycle.m, tempdir.m, optimset.m, pkg/pkg.m, closereq.m, colstyle.m, __fltk_print__.m, __gnuplot_print__.m, __go_draw_figure__.m, __pie__.m, __pltopt__.m, __print_parse_opts__.m, uigetdir.m, uigetfile.m, uiputfile.m, stft.m, mean.m, anova.m, cor_test.m, t_test_regression.m, __magick_read__.cc, dlmread.cc, schur.cc, data.cc, debug.cc, defun-dld.h, defun.cc, defun.h, dynamic-ld.cc, error.cc, error.h, gl-render.cc, graphics.cc, gripes.cc, input.cc, lex.ll, load-path.cc, load-save.cc, ls-hdf5.cc, ls-mat-ascii.cc, ls-mat4.cc, ls-mat5.cc, ls-oct-ascii.cc, ls-oct-binary.cc, oct-hist.cc, oct-parse.yy, oct-stream.cc, oct-stream.h, octave.cc, ov-base-diag.cc, ov-base.cc, ov-class.cc, ov-colon.h, ov-struct.cc, ov-typeinfo.cc, ov.cc, pager.cc, pr-output.cc, pt-binop.cc, pt-eval.cc, pt-id.cc, pt-idx.cc, pt-misc.cc, pt-unop.cc, symtab.cc, symtab.h, toplev.cc, txt-eng-ft.cc, utils.cc, variables.cc, test_eval-catch.m, test_try.m: Use ' instead of ` in error messages, warnings, and most comments.

--- a/src/pr-output.cc	Sun Sep 23 10:36:25 2012 -0700
+++ b/src/pr-output.cc	Mon Oct 01 17:18:49 2012 -0400
@@ -58,8 +58,8 @@
 #include "utils.h"
 #include "variables.h"
 
-// TRUE means use a scaled fixed point format for `format long' and
-// `format short'.
+// TRUE means use a scaled fixed point format for 'format long' and
+// 'format short'.
 static bool Vfixed_point_format = false;
 
 // The maximum field width for a number printed by the default output
@@ -3631,7 +3631,7 @@
                 }
               else
                 {
-                  error ("format: unrecognized option `short %s'",
+                  error ("format: unrecognized option 'short %s'",
                          arg.c_str ());
                   return;
                 }
@@ -3676,7 +3676,7 @@
                 }
               else
                 {
-                  error ("format: unrecognized option `long %s'",
+                  error ("format: unrecognized option 'long %s'",
                          arg.c_str ());
                   return;
                 }
@@ -3755,7 +3755,7 @@
           Vcompact_format = false;
         }
       else
-        error ("format: unrecognized format state `%s'", arg.c_str ());
+        error ("format: unrecognized format state '%s'", arg.c_str ());
     }
   else
     {