Migrate swig wrappers out to their individual modules

See the ./wrappers subdirectory for wrapper modules with an example in ./wrappers/example. Moved swig subdirectory to ./wrappers/old_swig, as it is no longer used in the build process, but is needed for further migration work and my be removed entirely after all modules are migrated into their own subdirectories
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Remove old swig implementation
Remove unused swig options and add missing line at section break
Merge branch 'develop' of /var/lib/git/opentxs into develop
Update includes locations
Update linked libraries for wrappers
Move required link libraries definition to ./wrappers/CMakeLists.txt - OTX_LINK_LIBS for further automation. Each wrapper's individual CMakeLists.txt file now uses  to get link requirements.
Missed example wrapper
Merge pull request #88 from BlueWall/develop

Migrate swig wrappers out to their individual modules
Moved OTPayment and InstantiateContract into ext.
Moved out cash next to core.