Should not pass value of `$PROCFS` (close #622)
Should not pass value of `$PROCFS` (close #622)

This is picked from squaremo/weave@d3cc606d5b356dff59ce2ab8304d8b54b27a61b9

The environment variable `PROCFS` was originally added so that the script
could be run in a container. The host's /proc is bind-mounted as /hostproc,
and the script must be told this.

The remote weaving changes got this a bit wrong, by using the value of
`$PROCFS` in a "volume" mount argument (`-v`) to docker -- but when
invoking a container, the left-hand-side of the volume mount should
*always* be `/proc` (and the right-hand-side always `/hostproc`),
since it will always be binding the host's `/proc` to the container's
`/hostproc`.

The gist is that docker looks at host's root filesystem and if you
pass `-v /hostporc:/hostproc` when running from a container where
you have already bind-mounted it, it will end-up creating empty
directory in the target container as there is no `/hostproc` from
docker's perspective.

ycaihua/weave,paladin74/weave,BWITS/weave,squaremo/weave,n054/weave,paulbellamy/weave,tomwilkie/weave,beni55/weave,narry/weave,errordeveloper/weave,cgvarela/weave,bboreham/weave,awh/weave,paulbellamy/weave,rade/weave,awanke/weave,narry/weave,cgvarela/weave,awanke/weave,paladin74/weave,squaremo/weave,paulbellamy/weave,bboreham/weave,ycaihua/weave,aaam/weave,philipz/weave,2opremio/weave,bboreham/weave,philipz/weave,errordeveloper/weave,achanda/weave,ycaihua/weave,dpw/weave,aaam/weave,rade/weave,BWITS/weave,OnePaaS/weave,paladin74/weave,inercia/weave,bboreham/weave,narry/weave,errordeveloper/weave,narry/weave,weaveworks/weave,2opremio/weave,squaremo/weave,n054/weave,aaam/weave,n054/weave,rade/weave,dpw/weave,BWITS/weave,2opremio/weave,paladin74/weave,dpw/weave,weaveworks/weave,weaveworks/weave,awh/weave,kidaa/weave,achanda/weave,tomwilkie/weave,achanda/weave,narry/weave,2opremio/weave,kidaa/weave,ycaihua/weave,beni55/weave,paulbellamy/weave,tomwilkie/weave,dpw/weave,ycaihua/weave,kidaa/weave,aaam/weave,OnePaaS/weave,philipz/weave,tomwilkie/weave,achanda/weave,OnePaaS/weave,philipz/weave,BWITS/weave,n054/weave,awanke/weave,rade/weave,rade/weave,inercia/weave,beni55/weave,squaremo/weave,weaveworks/weave,awanke/weave,errordeveloper/weave,aaam/weave,awh/weave,kidaa/weave,awh/weave,philipz/weave,beni55/weave,2opremio/weave,inercia/weave,awanke/weave,beni55/weave,BWITS/weave,n054/weave,tomwilkie/weave,cgvarela/weave,errordeveloper/weave,squaremo/weave,kidaa/weave,awh/weave,OnePaaS/weave,paladin74/weave,inercia/weave,cgvarela/weave,bboreham/weave,inercia/weave,OnePaaS/weave,dpw/weave,achanda/weave,cgvarela/weave