DLL release

Add xinput1_3.dll proxy for automatic start (Method 4)

A proxy xinput1_3.dll dropped next to a game launches xinagg360.exe
hidden, holds the game's first XInput call until the virtual pad exists,
then forwards every export to the real DLL. The aggregator now exits
when the game does (--parent-pid), holds a guard mutex so the proxy
never starts a second copy, and loads XInput from System32 so it does
not pick up its own proxy.

Also: gitignore build output and compiler leftovers, untrack pycache,
link xinhome and emuCenter in the README.