Added 3 unicode pages for font, fixed UI, added Block.breakable

Added 1, 2, 3 and 4 unicode pages from Minecraft.
Font now uses std::wstring instead of std::string
Added Block.breakable field (the only unbreakable block is bedrock)
Bedrock is now selectable

src/voxels/Block.h

@@ -14,6 +14,7 @@ public:
 	bool skyLightPassing = false;
 	bool obstacle = true;
 	bool selectable = true;
+	bool breakable = true;
 
 	Block(unsigned int id, int texture);
 };