Torrents are now considered stopped and may be restarted even if
the stop event haven't been sent the trackers yet. The same holds
for the del and add commands.

A btpd process in shutdown mode that only have stopped torrents,
but is still sending the stop event to trackers, will release
resources that would block a new btpd to start. It will the
silently exit when it's finished with the trackers.

This also makes the timeout parameter for shutdown unnecessary.

improved error output.

The add and del commands adds or removes torrents from this library.
The start and stop commands are used to active or deactivate torrents.
Also, a mechanism for qeurying data on torrents has been added. It's
only used by the btcli list and stat commands yet though.

btcli has been split into different files for each command.

Both btpd and btcli now use misc/btpd_if.h for all ipc definitions.

Misc changes:
- struct metainfo is gone. Use the new mi_* functions.
- Add printf format type checking where appropriate.