Fix of

"Unicode char like for example "ł" crush app when used in profile name"
https://github.com/prusa3d/Slic3r/issues/388

The Prusa3D binary builds are missing the UTF8 libraries.
To avoid having to bundle them, the case sensitive regexes testing
file suffixes were replaced with explicit enumeration of lower / upper
case letters. While crude, it avoids triggering the UTF8 library.

utils/split_stl.pl

@@ -27,7 +27,7 @@ my %opt = ();
 {
     my $model = Slic3r::Model->load_stl(Slic3r::encode_path($ARGV[0]), basename($ARGV[0]));
     my $basename = $ARGV[0];
-    $basename =~ s/\.stl$//i;
+    $basename =~ s/\.[sS][tT][lL]$//;
     
     my $part_count = 0;
     my $mesh = $model->objects->[0]->volumes->[0]->mesh;