maint: Capitalize variable names appearing in error() messages of m-files. * scripts/audio/@audioplayer/get.m, scripts/audio/@audiorecorder/get.m, interp1.m, narginchk.m, nargoutchk.m, randi.m, __fltk_file_filter__.m, imshow.m, rgbplot.m, javachk.m, usejava.m, condest.m, unpack.m, pqpnonneg.m, savepath.m, default_prefix.m, get_forge_download.m, get_forge_pkg.m, installed_packages.m, annotation.m, daspect.m, pbaspect.m, isocaps.m, pan.m, printd.m, __gnuplot_draw_axes__.m, rotate.m, rotate3d.m, zoom.m, splinefit.m, addpref.m, getpref.m, rmpref.m, eigs.m, normrnd.m, t_test_regression.m: Capitalize variable names appearing in error() messages.

--- a/scripts/miscellaneous/unpack.m	Thu Oct 27 09:24:58 2016 +0200
+++ b/scripts/miscellaneous/unpack.m	Mon Nov 14 12:12:02 2016 -0800
@@ -90,7 +90,7 @@
       ## FIXME: The above code is not a perfect test for a URL
       gfile = glob (file);
       if (isempty (gfile))
-        error ('unpack: file "%s" not found', file{1});
+        error ('unpack: FILE "%s" not found', file{1});
       else
         file = gfile;
       endif