grid/grid.go: Only generate tiles on move
Revert "Now deleting tiles next move so that we can animate the merge"

This reverts commit c64518120fbf920920fa02c3f4c38ab78f2b1bd9.

Conflicts:
	grid/grid.go
Readd merged status
SQL storage and stuff.
Remove unneeded types
Refactoring some of the types
Move DB connection to main method