mtcp: Keep track of number of queues attached to ps_handle

Signed-off-by: Anup Patel <anup@brainfault.org>
io_engine: netmap: Fix default netmap include directory in Makefile

Signed-off-by: Anup Patel <anup@brainfault.org>
apps: Update all apps to reflect directory structure changes in io_engine

Signed-off-by: Anup Patel <anup@brainfault.org>
mtcp: Improve return value check of ps_list_devices() in mtcp_init()

Signed-off-by: Anup Patel <anup@brainfault.org>