Structure Construction

The following things need to happen for structure construction:

X Finalize the building yaml syntax - Include turns to build
X (server Only at the moment) Dynamically load all structures in the structure directory
X Reenable tile coordinate acquisition by left click
- A building selection widget for the GUI
X List will be generated in right click menu for the tile
- A build icon, as well as tile boarder glow effect or something similar
X Move tile grid to server and communicate via standard methods to client
X Pull construction graphic for all buildings being built
X Buildings being built (the structure objects) should go in a list (in addition to the grid) so
X Turn timer will process list and structure objects will update their turn's left
X structure class will switch graphic to standard graphics upon completion

For release 0.8
Structures will need prereq materials (from mining/refining) to be built
For release 0.11
Structures will need prereq research to be built