starting to cleanup extern 'c' mess
add libunbound headers

to silences msvc compiler & get us a bit further into build process
msvc build fixes for crypto.lib

- cleanup extern "C" mess
- put crypto stuff into crypto namespace
- some explicit typecasts
fix one more extern c declaration
move initializer list to impl

msvc does not like this in the header for some reason
libupnp needs static linkage with msvc
Merge pull request #1 from tugwert/master

MSVC build fixes up to where libunbound is really missing