Add attach command to weave.
attach command that accepts and existing container id and runs configure_container_networking using it
Remove veth and/or netns symlink if interface configuration fails part-way through
untabify
fix subshell syntax and make del/delete consistent
return not exit from function
untabify
Take out debugging -x mode
Merge branch '61_cleanup_script' of https://github.com/bboreham/weave into bboreham-61_cleanup_script
note that local traffic isn't captured
cosmetic
Filter outbound packets in the kernel

It turns out that under Linux, libpcap implements the SetDirection
filtering in userspace, causing some spurious wake ups of the packet
capture thread.  So set a BPF filter to discard outbound packets inside
the kernel.
Merge branch 'dpw-65_prevent_recapture'

Closes #65
Don't test if symlink exists before 'rm -f'
When the symlink's target doesn't exist, '[ -f' is false, so the symlink doesn't get removed.
Since we do always want it to be removed, just call 'rm -f' anyway, which won't complain
if the file doesn't exist.
If and only if network setup because the container died, say so.
This involves capturing stderr output from all the 'ip' commands so we
can hide that output if we see the process died, or show it to the user
if the process didn't die, in which case we don't know why we failed.
Tidy up messages; ensure errors to to stderr
cosmetic
rm tempfile before we use it, to avoid attack via symlink
Merge branch '61_cleanup_script' of https://github.com/bboreham/weave into bboreham-61_cleanup_script
cosmetic