Log Message:
o Simplify MASTER_SITES (removing VERSION) and use the one suggested on HOMEPAGE
o Switch to .tar.gz distfile
o Add a COMMENT
o Add a py-docutils to BUILD_DEPENDENCIES in order to generate the man page
 (rst2man is needed for that). Properly handle the man page via --mandir
 WAF_ARGS.
o Set PYTHON_FOR_BUILD_ONLY (it is only needed for waf)
o Other minor cosmetic fixes

XXX: Thomas, should we treat waf as a CONFIGURE_SCRIPT? Do you know how other
XXX: packages in pkgsrc communicates with waf?