Fixed Recon Centre not visible in building menu.

Fixed Recon Centre not showing in the construction menu.

Fixed not being able to send colonists underground.

Fixed Recon Centre not detecting new asteroids.

Made it so spires require exotic minerals for construction.

Made it so spires require exotic minerals for construction.

Adjustments to tech tree.

Adjustments to tech tree.

Rebalanced the Recon Centre.

Fixed not being able to send colonists underground before Underground Domes tech was researched.