and provide backwards compatibility for sha1, and also added
md5 to complete the RFC 4122 spec implementation
as such, boost::uuids::name_generator is deprecated, however
still defined to use the same implementation in previous boost
releases, and name_generator_sha1 as well as name_generator_md5
now exist, in preparation for whatever will replace sha1.
to properly test the new header structure, I took the bjam
rule from winapi to isolate each header as an include and make sure
it has no dependencies on other headers to be included first,
and was able to remove a few test files that became unnecessary.
This fixes#26
