Add a prefix to all symbols in libmd to avoid incompatibilites
with same-named, but not binary compatible, symbols from libcrypto.
Also introduce Weak aliases to avoid the need to rebuild dependent
binaries and a major version bump.
PR: 199119
Differential Revision: D2216
Reviewed by: roberto, delphij
MFC after: 2 weeks
Imported libmd. This library contains MD2, MD4 and MD5.
These three boggers pop up all over the place all of the time, so I
decided we needed a library with them. In general they are used for
security checks, so if you use them you want to link them static.