Fixes for data collection & annotation interfaces

Resolves #52 (closed) Annotation GUI detects ambiguous horizontal single-stud connection and prompts the user for more information. Internally, the system 'hallucinates' one extra stud connection so the relative translation between blocks can be recovered without changing the existing state parser.

Resolves #49 (closed) Participant birth year field in data collection GUI is now user-configurable. config/participant_birth_years.txt determines the range of years to display by specifying the min and max. Configuration settings are now documented in config/README.