Removed the unused "rfc/prelude.h" header file.
Added links to relevant RFC specifications to the TODO file.
Defined the RFC 1321 (MD5) and RFC 3174 (SHA-1) modules.
Defined the RFC 3986 (URI) and RFC 4122 (UUID) modules.
Amended the installation instructions for FreeBSD and Mac OS X.
Defined the rfc1321::md5 structure.
Added a static assertion to ensure sizeof(md5) is correct.
Implemented the relational operators for the md5 struct.
Defined the md5::compute() method.
Implemented the md5#data() method.
Implemented the md5#compare() method.
Implemented the md5#clear() method.
Defined the md5::size constant.
Implemented the md5#operator[] method.
Implemented the md5#swap() method.
Implemented the md5#front() and #back() methods.
Ensured that md5#operator[] returns a reference.