Improve test framework: create_file

create_file '-' sends to standard output
create_file --label=LABEL
create_file passes other options to tfw_createfile
Improve testdefs_meshms.sh: meshms_add_messages

meshms_add_messages() puts message texts into TEXT[$n] array
instead of "text$n" files
fixup! UNFINISHED Java API MeshMS message list