Implement serialization, export controller
Add import/export of layouts
Update documentation, bump version number
Merge branch 'release/1.2.0'
Merge tag 'v1.2.0' into develop

Version 1.2.0. Tested with: Firefox 32.0.
Add half shapes and 9v tracks
Fix some shapes, add more
Bump version number, update documentation
Merge branch 'release/1.2.1'
Merge tag 'v1.2.1' into develop

Version 1.2.1. Tested with: Firefox 32.0.