Solid data is moving from the server to the client, read more

The APIs have access to the solid data, and I fixed a bug: Basically, the
template parameter for std::bitset  expects an integer representing the
number of bits to hold, but I initially misread it as the number of bytes.
This has been corrected.

I've also added a sandy beach to the generated island. I'm tempted to
start working on some simple generators soon.

common/map/region.cpp

@@ -35,6 +35,7 @@ Region::Region(int argX, int argY): x(argX), y(argY) {
 
 Region::Region(Region const& rhs): x(rhs.x), y(rhs.y) {
 	memcpy(tiles, rhs.tiles, REGION_WIDTH*REGION_HEIGHT*REGION_DEPTH*sizeof(type_t));
+	solid = rhs.solid;
 }
 
 Region::type_t Region::SetTile(int x, int y, int z, type_t v) {