Log Message:
math/mcsim: Make sure package doesn't try to use tex and friends

Although mcsim.dvi, mcsim.html, and mcsim.texinfo aren't on the PLIST, the
package tries to build them anyway, at least on DragonFly.  This modifies
the documentation makefile to prevent this.  DragonFly doesn't have dvips
and thus the package was failing to build.