Use matrix concatenation for strings, rather than cstrcat(), for clarity and performance. matrix concatenation is ~80% faster than cstrcat(). * doc/interpreter/strings.txi: Document preference for matrix concatenation as opposed to alternatives. * doc/interpreter/geometryimages.m, doc/interpreter/interpimages.m, doc/interpreter/plotimages.m, doc/interpreter/sparseimages.m, doc/interpreter/splineimages.m, scripts/general/genvarname.m, scripts/general/int2str.m, scripts/general/num2str.m, scripts/help/__makeinfo__.m, scripts/help/help.m, scripts/miscellaneous/copyfile.m, scripts/miscellaneous/dir.m, scripts/miscellaneous/edit.m, scripts/miscellaneous/fact.m, scripts/miscellaneous/fullfile.m, scripts/miscellaneous/mkoctfile.m, scripts/miscellaneous/movefile.m, scripts/miscellaneous/perl.m, scripts/miscellaneous/python.m, scripts/miscellaneous/run.m, scripts/miscellaneous/tempdir.m, scripts/miscellaneous/unpack.m, scripts/pkg/private/configure_make.m, scripts/pkg/private/create_pkgadddel.m, scripts/pkg/private/extract_pkg.m, scripts/pkg/private/get_description.m, scripts/pkg/private/get_forge_pkg.m, scripts/pkg/private/getarch.m, scripts/pkg/private/getarchprefix.m, scripts/pkg/private/install.m, scripts/pkg/private/installed_packages.m, scripts/pkg/private/load_packages_and_dependencies.m, scripts/pkg/private/rebuild.m, scripts/pkg/private/repackage.m, scripts/pkg/private/shell.m, scripts/pkg/private/uninstall.m, scripts/plot/private/__go_draw_axes__.m, scripts/signal/spectral_adf.m, scripts/signal/spectral_xdf.m, scripts/statistics/tests/z_test.m, scripts/statistics/tests/z_test_2.m, scripts/strings/mat2str.m, scripts/strings/strtok.m, scripts/testfun/__run_test_suite__.m, scripts/testfun/assert.m, scripts/testfun/demo.m, scripts/testfun/speed.m, scripts/testfun/test.m, test/eval-catch.tst, test/io.tst, test/try.tst: Replace cstrcat() with matrix concatenation where possible.

--- a/scripts/general/genvarname.m	Wed Jul 17 10:09:44 2013 -0700
+++ b/scripts/general/genvarname.m	Wed Jul 17 14:02:32 2013 -0700
@@ -119,7 +119,7 @@
     error ("genvarname: STR must be a string or a cellstr");
   endif
 
-  validchars = cstrcat ("A":"Z", "a":"z", "0":"9", "_");
+  validchars = ["A":"Z", "a":"z", "0":"9", "_"];
 
   varname = cell (size (str));
   for i = 1:numel (str)
@@ -130,7 +130,7 @@
     str{i}(! ismember (str{i}, validchars)) = "_";
     ## do not use keywords
     if (iskeyword (str{i}))
-      str{i} = cstrcat ("_", str{i});
+      str{i} = ["_" str{i}];
     endif
     ## double underscores at the beginning and end are reserved variables
     underscores = (str{i} == "_");
@@ -145,7 +145,7 @@
     endif
     ## it cannot start with a number
     if (ismember (str{i}(1), "0":"9"))
-      str{i} = cstrcat ("_", str{i});
+      str{i} = ["_" str{i}];
     endif
 
     ## make sure that the variable is unique relative to other variables