I used the code in `wiiu/` to bootstrap my own WiiU homebrew app; this
PR reflects some changes I needed to make, that might be useful upstream.
1. Clean up filesystem initialization
Filesystem driver initialization was lumped in with filesystem mounting;
and that was a problem in my project, because I needed to be able to remount
the SD card on the fly. So, now it's split up.
I've added a callback object named "hooks" that can be used by consuming
applications to handle filesystem mounting and unmounting. If these hooks are
not provided, then the existing default behavior occurs.
2. Expand socket handling
- add `SO_NONBLOCK` flag for non-blocking socket I/O
- add normal errno defines like `EWOULDBLOCK` `EAGAIN`.
3. Remove RetroArch dependencies
- the exception handler protects usage of version_git with
`#ifdef HAVE_GIT_VERSION` but not the include, so I added that.
It also technically depends on version.h, but I'm not touching that.
It's easy enough to implement and I needed the same functionality. I'm
not sure what the best solution for that dependency is.
- missing_libc_functions.c included features/features_cpu.h which is
a libretro include. This appears to be a stale include though, because
everything compiles and works without it.
- an ifdef referencing the RA "WIIU" define, rather than the devkitpro
"__wiiu__" define
