cppcheck: include headers for better checking

In a first step the headers are included for checking opentxs-api.
Eventually, the include arguments will be integrated into
cppcheck_wrapper.sh which will be called only once as it was before.
Merge pull request #24 from toxeus/cppcheckAPI

cppcheck: include headers for better checking
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