Merge branch 'release/2.0' into develop
Bumped version number to 2.0dev
Renamed is_airviro_system() in the system module to is_airviro()
Added a concept of Airviro version to the system module
Added a hidden Airviro version attribute to model fields
Made the Model meta class only use fields for the current Airviro version

- Added a _get_current_fields() method to the Model meta class.
- Modified the rest of the package to use the above method, where
  appropriate.
Merge branch 'topic/versions' into develop

- This merge introduce a concept of Airviro versions.
Made it possible to create Edb instances on non-Airviro systems
Added a version property to Edb instances
Made the system module search for current Airviro version

- Changed the LATEST_VERSION attribute to DEFAULT_VERSION.
Made the Model class's serialize methods take an explicit version
Added a version option to the ModelReader and ModelWriter
Merge branch 'topic/versions' into develop

- Remade the Airviro version implementation to handle edb-specific
  versions.
- Made the system module use /usr/aiviro/system/avinfo to find the
  current Airviro system version.
Fixed a bug in the retreival of the Airviro system version
Added three new ship ALOB properties and removed six describing usage
Bumped version number to 2.1dev
Added a --version option to the sourceLookup and sourceResolve tools
Made lookupservices' http fetchers handle communication failures better
Added a TUR2014 ship resolver for the Turkey project
Added a set_me_stroke_type callback to the IHS lookupservice