This patch redesign the original getadapter plugins. Currently,
getadapter do not work as a common command but only a chain command
works during discovery.
Currently the getadapter implementation store the nics information
in multiple files. This implementaion will store the records in the
database and add the following changes:
1. Add taskstate table to record the getadapter request.
2. Add route_request hook in xcatd to avoid of too much process.
3. Add adapterinfo column to keep the adapter information.
4. Use fifo pipe to send/recv the adapter message and wake up the waiting process.
5. Use alarm signal to handle the timeout event.
