CMake: build anyoption as library

This way it is not compiled with the very strict compiler flags
used to compile opentxs code.
opentxs: fix -Wold-style-cast
Merge pull request #267 from toxeus/fixOldCasts

opentxs: fix -Wold-style-cast
OTAccount: move shared functions into Helpers.hpp
CMake: Packaging: Add number of commits since last tag in version string (file name)
Merge pull request #269 from lclc/packageName

CMake: Packaging: Add number of commits since last tag in version string...
Merge pull request #270 from toxeus/createHelper

OTAccount: move shared functions into Helpers.hpp