Replace: CScript::mscore_getHex() and CScript::mscore_parse()

There was exactly one use of CScript::mscore_getHex(), so it was replaced to reduce the impact on Bitcoin Core. Instead of using a modified version of CScript::ToString(), CScript::mscore_parse() was replaced by an external function, which collects pushed values in a script.

The original state of script.h is now contained.

Build confirmation:
https://travis-ci.org/dexX7/mastercore/builds/45404574

The other friends on TODO: GetScriptForDestination(), GetScriptForMultisig() and maybe GetDustLimit().