* changed vfs_root_register's name because the _mount didn't add anything
* removed the old pointless vfs_backend_tryaccept calls from drivers
* because of that, i could remove the vfs_backend globals
* replaced the horrible BACKEND_KERN macro
* all vfs_backends are now stored on the heap
I was reading from the buffer as if the WRAP flag was enabled, but it
actually isn't supported with a 64K buffer.
Besides, if it worked correctly, then the code for updating the ring
position would land in the wrong place, because it didn't take WARP
into account.
