Portability tweaks for the build.

Portability tweaks for the build.

  - pull in cvstools/Makefile.incl, mainly so that we can use
    cvstools/runtrang

  - "trang" -> $(RUNTRANG) so that cvstools/runtrang is used; if
    users don't have trang binary installed, that will find
    trang.jar and run it. Also allows users to manually specify
    what trang they want (e.g., "make RUNTRANG=trang")

  - "clean" target now also removes dbforms* files

  - "clean" target now also does "make -C build clean"

  - "xsltproc" -> $(XSLTPROC)