[proxy] use exec instead of run, to replace weavewait with subprocess
[proxy] use exec instead of run, to replace weavewait with subprocess

Closes #708

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