A rewrite and such

This update effectively replaces the extension with a slightly better version of it, at expense of my weekend:

• The extension now has a 64-bit version.
• The extension no longer uses an additional executable, instead resorting to running itself as a new process via rundll32.
• Perhaps consequence of above, the extension is no longer being considered a virus by random antiviruses that I’ve not heard of.
• In line with my other recent efforts, the DLL is now much smaller (16KB for x86 version, 19KB for x64 version).
• Window Commands functions now work when frame is disabled (which means that you can minimize the game without re-enabling the frame).
• The code is now slightly less scary, though don’t get too excited.
• Exiting fullscreen no longer causes the frame window to act unusually.
• The demo has been rewritten and now uses GMS2.3 (but feel free to backport it and submit a PR if it seems important).
• I added a few utility functions and documented a few more.
• Documentation now spots a list of things that are known to not play well with this extension.

And that’s likely all I can do with this! If you have sufficiently deep knowledge of WinAPI, you could potentially fix some of the issues, but I don’t, so this is how it is.