v5.0.0-alpha Optimize file input and stdout output

Attempt to fix #20 by using two more performant Emscripten APIs, FS.writeFile instead of Fs.createDataFile+intArrayFromString, and for output Module.print instead of Module.stdout.

I don't think this should be a breaking change, for most people at least, but I'm doing a major version bump anyway because I think maybe the createDataFile vs writeFile change could cause trouble if the input XML had some other encoding than utf-8. FS.writeFile assumes utf-8 when the input is string.

TODO: We now also accept Buffer in the XML file contents, which should be reflected in types. Also, more testing is needed before release, I haven't checked browser usage at all yet.

4.0.2

Minor improvement to error handling (#19, 012dde34b).

4.0.1

Fix to the TypeScript type definitions (#16).
No runtime changes.

4.0.0

Add two new options, initialMemoryPages and maxMemoryPages, to control
how much memory the WebAssembly module allocates by default and is allowed
to allocate for the validation.
PR #16, fixes issue #8.
Thanks @MLSTRM!

The "breaking change" here is that we also raise the default maximum
memory cap from the old implicit 16MiB to double of that, 32MiB.
With this new default, you may not even need to use the maxMemoryPages option
yourself, as 32MiB is probably already high enough for quite a lot of use cases.

In some very memory constrained environments, this raised limit could impose
a problem if it causes the main process to run out of memory, so that's why
I'm calling it a breaking change. For most applications, though, this should
not be a problem. You can opt into the old limit by setting

  maxMemoryPages: 16 * xmllint.memoryPages.MiB,