added HACKING file.
add export visibility symbols and set everything to internal visibility by default.
Merge branch 'master' into develop
Additional exports.
Merge pull request #46 from evoskuil/develop

Additional dll exports.
remove function definitions from .ipp files - they don't belong there.
Add defines to common libbitcoin header.
Merge pull request #47 from evoskuil/develop

Add defines to common libbitcoin header.
ripemd160 files with slight derived from openbsd hash/rmd160.c
integrate ripemd without openssl
make autogen.sh +x
add new testnet dns seeds.
sha1, sha256, ripemd160 without openssl
use boost for endian tests in hash fns
Remove for loop initializers from C code.
update includes and fix one parameter
fix lousy macro declarations
missed conditionally-compiled macro call
Merge pull request #1 from evoskuil/develop

sha1 and ripemd160 from openbsd, sha256 from libsodium
bugfix: makefile not install external/ headers into subdir