Modify mz.inflate() to remove malloc()

There's a callback parameter to receive the data as it's decompressed.
Fix tstzip.lua to use new mz.inflate() code.
Use a callback to feed mz.inflate().

So now mz.inflate() takes two functions, the first one to source data, and
the second one to sink data.

And modify tstzip.lua to use the updated mz.inflate() method.