Renamed file to make it non-executable.
Turned off executable commands so that this can't be used to execute code on the server.
Tweaked source name to bring it in line with what we have in the tree2tabled.tar.bz2 file.
Added an error message for when a pre-processed tree cannot be found.
Added more error messages for (1) blank final trees, and (2) when this tree is not installed.