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/liboctave/file-ops.cc	Sun Sep 23 10:36:25 2012 -0700
+++ b/liboctave/file-ops.cc	Mon Oct 01 17:18:49 2012 -0400
@@ -117,13 +117,13 @@
 file_ops::tilde_expansion_hook file_ops::tilde_expansion_failure_hook = 0;
 
 // When non-null, this is a NULL terminated array of strings which are
-// duplicates for a tilde prefix.  Bash uses this to expand `=~' and
-// `:~'.
+// duplicates for a tilde prefix.  Bash uses this to expand '=~' and
+// ':~'.
 string_vector file_ops::tilde_additional_prefixes = default_prefixes;
 
 // When non-null, this is a NULL terminated array of strings which
 // match the end of a username, instead of just "/".  Bash sets this
-// to `:' and `=~'.
+// to ':' and '=~'.
 string_vector file_ops::tilde_additional_suffixes = default_suffixes;
 
 // Find the start of a tilde expansion in S, and return the index
@@ -221,7 +221,7 @@
   if (f_len == 0 || filename[0] != '~')
     return filename;
 
-  // A leading `~/' or a bare `~' is *always* translated to the value
+  // A leading '~/' or a bare '~' is *always* translated to the value
   // of $HOME or the home directory of the current user, regardless of
   // any preexpansion hook.