CMake: use system's ZMQ includes
Merge pull request #19 from toxeus/zmqIncludes

CMake: use system's ZMQ includes
Some anyoption related changes:
- Added AnyOption::findOption
- Moved anyoption.cpp to api lib
- Replaced #include <anyoption.hpp> in opentxs.hpp with class AnyOption;
- Changed #include <anyoption.hpp> to #include <anyoption/anyoption.hpp>
  to remove specific dependency_include_dir
Some renaming and reordering of standard arguments in opentxs.cpp
Switch to stream logging in opentxs.cpp
One class per opentx command
Moved most of ot_commands_ot.cpp to correct CmdXxx.cpp