initial ECDH implementation
initialize jwt
cleanup
cleanup EC code
winlib: initial ECDH port to Windows

Conflicts:
	libbrowserid/bid_crypto.c
	libbrowserid/bid_openssl.c
only interpose crypto if we have claims
winlib: ignore unknown reg value types
remove cruft (_CNGTranslateKey)
update protocol for ECDH
remove ulECDHCurve, unused