Added bitcoin-base58 library.
Use base58Check instead of base62.
New ID format: OT-[base58Check with version byte 0].
Renamed functions s.t. they do not mention base62 anymore.

Also fixed up some comments that are not accurate anymore.
Use the (ripemd160 . sha256) hash algorithm for identifiers.
Merge pull request #348 from benma/base58

New ID format: OT-(base58Check encoded)
Temp workaround for broken versioning for OSX.
Merge pull request #351 from murrekatt/cmake_versioning_fix

Temp workaround for broken versioning for OSX.
Fixed int64_t format to use PRId64.
Merge pull request #352 from murrekatt/format_fixes

Fixed int64_t format to use PRId64.
Fix build without CHAI script
use variable for openssl libraries in deps
Merge pull request #353 from mhamrle/fix_missing_includes

Build for android part 1
use stable repo for libzmq
Merge pull request #354 from mhamrle/use_stable_zmq

Use stable repo for libzmq
unify include lite protobuf headers
Merge pull request #356 from mhamrle/unify_protobuf_headers

unify include lite protobuf headers
Introduce ANDROID_UNUSED

In android build configuration some function params is not used but they are used in other builds. This commit adds new macro ANDROID_UNUSED that supress warnings.
callback is not used in android build
fix print format