introduce ecdsa_address_to_hash160
rework ecdsa_address_to_hash160 into ecdsa_address_decode
split signing into ecdsa_sign_digest and ecdsa_sign/ecdsa_sign_double
add ecdsa_sig_to_der
introduce uncompress_coords
introduce ecdsa_verify_digest
introduce point_multiply
fix ecdsa_sig_to_der
use -Wextra
llu -> ull for MSVC compatibility
remove field name struct init for MSVC compatibility
Merge pull request #4 from jpochyla/master

MSVC compatibility fixes
add cmake file with c++ compilation on MSVC
Merge pull request #5 from jpochyla/master

Add CMake file with c++ compilation on MSVC
use both private and public bip32 versions
replace SHA256/SHA512 prefix with sha256/sha512 (OpenSSL clash)
fix prefixes in internal functions as well
get rid of bip32 versions, it's a mess :(
new test to compare private and public branch of bip32
remove version_byte and address from bip32