Merge tag 'v0.1.2' into develop

- Enforce pop cap when building units.
- Enforce resource limits for techs and units.
- Display game errors (housed).
- Display currently selected units.
Make delegate for building units/techs/buildings in state, so that advancing the time etc can be done at the same time.
Enforce resource limits for constructing buildings - fixes #27
Make entire TaskCount widget clickable - fixes #30
Make assigning initial task optional.
Builders can be reassigned to other tasks after building - fixes #2.
Bump version.
Merge branch 'release/v0.1.3'