CMake: used ZMQ shared lib for opentxs shared lib

In the switch to use the system's libzmq we preserved the
statically linking of it. But since all other library dependencies
are linked as shared libraries libzmq should be as well.
Then, third party library linking is consistent when building our
own shared library.
Merge pull request #6 from toxeus/sharedZMQ

CMake: used ZMQ shared lib for opentxs shared lib
Removed Windows warning about GCC pragma
Fixed crash in OT-Armor decompression when trying to decompress plaintext
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
Removed unused parameter from OT_Command::details_refresh_nym
Aligned colons in output in MadeEasy::stat_asset_account
Some renaming and reordering of standard arguments in opentxs.cpp
Switch to stream logging in opentxs.cpp
Fixed several functions that return an amount to return OT_ERROR_AMOUNT
 instead of -1 which could be a valid amount.
 This was an artifact of the conversion from string to int64_t.