* Use a regular expression to enforce more stringent bus label testing.
* Add validator to edit label dialog to prevent space character from being
used in labels.
File "rules" has instructional text as comments near top.
2) Convert all text files in repo to LF line ending form.
Any checkout done with "rules" in play will convert the working
tree to native line ending, while keeping repo as LF line ending.
subclass DIALOG_SHIM support.
Tried dialog_drc but it has nesting problems due to use of DRCLISTBOX, which
needs to be put into its own header file to untangle.