Added a new command 'weave status', implemented via an http listener #11
ran 'go fmt'; cosmetic changes
Merge remote-tracking branch 'upstream/master' into 11_http_interface
Remove boilerplate and condense the http handler down to one function.
Also fixed indenting on one line in shell script.
Merge remote-tracking branch 'upstream/master' into 11_http_interface

Conflicts:
	weaver/weave
Add back the usage test for two arguments, except when the command is 'status'
Pull out ugly 'command -v' code to a utility function
Merge remote-tracking branch 'upstream/master' into 11_http_interface

Conflicts:
	consts.go
	weaver/weave
Convert one further use of 'command -v' into the function command_exists
Addressed various points raised in review: error-handling, simplified Fprint call
Improved error message on http ListenAndServe
Swap round 'status' and 'stop' in usage
Add ‘weave status’ to the README
Merge pull request #17 from bboreham/11_http_interface

add 'weave status'

closes issue #11