Add love.data module.

- Moved love.math.compress / decompress / decode / encode / hash to love.data.
- Changed love.data.compress/decompress to take the format argument first instead of second.
- Added love.data.newDataView. Returns a read-only subsection of an existing Data object.
- Added love.data.newByteData. Mostly useful in combination with LuaJIT's FFI as it has no extra methods currently.
- Added implementations of Lua 5.3's data packing APIs: love.data.packString / packData / unpack / getPackedSize.

Resolves issue #1336.
Resolves issue #1331.

--HG--
branch : minor

src/scripts/boot.lua

@@ -387,6 +387,7 @@ function love.init()
 			highdpi = false,
 		},
 		modules = {
+			data = true,
 			event = true,
 			keyboard = true,
 			mouse = true,
@@ -453,6 +454,7 @@ function love.init()
 
 	-- Gets desired modules.
 	for k,v in ipairs{
+		"data",
 		"thread",
 		"timer",
 		"event",