here you can get a simple VFS system (yep, another one!). it
introduces `VFile` struct (kinda like `std.stdio.File`, but with
less features), which can wrap your own custom streams,
`std.stdio.File`, libc `FILE*`, integer file descriptor...
actually, anything you'll do a simple wrapper for. it's designed
in the spirit of `fopencookie()`.
also it includes VFS features like "pak file registration", and
built-in ZIP reader.
ZIP reader doesn't use `std.zip`, and doesn't unpack the whole
file in memory. it is even possible to register ZIP inside ZIP as
"pak" file! ;-)
also, it has functions to read and write numbers of various sizes
in both endiannesses.
VFile i/o is thread-safe (but not VFile itself!)
works with DMD 2.070+
GNU GPL. i wanted you to read the whole text to find this, yeah.