Re: MKDIR_P -> MKDIR-P?

Harlan asks:

> Why did the variable names change?

Consistency.  We used to have both '-' and '_' as separators
in our XML, e.g. <check-manifest> and <MKDIR_P>.  We now
always use '-' as the separator on the XML side (which is
consistent with common XML practice), and we always
downshift s/-/_/g to get variable/method names.

You can also reliably upshift s/_/-/g to turn a
method/variable name into a field-name to look for in XML
land.

Will