buffer.free: call return_virtio_buffer directly
transmit_packets_to_vm: localize more
net_device: % -> band
allow lib.malloc to take ffi.typeof'd argument, use that inside loops
transmit_packets_to_vm: temporary variable was global
memory is a global module now
memory init: call lib.hardware.bus to set appropriate allocator
new memory.malloc (utilizing either C.malloc or dma_alloc). Use it in lib.malloc
packet: kill packets array, use memory.alloc for packets allocation
Merge pull request #229 from llelf/main2

speed-ups
net_virtio: fix dpdk get buffer

The DPDK's virtio PMD is provoding a 1 descriptor buffers.
Detect and support this case.

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>