fix server sub / unsure stream logic and make sure there is only one active stream per doc
fix server sub / unsure stream logic and make sure there is only one active stream per doc

gdseller/ShareJS,kustomzone/ShareJS,Nzaga/ShareJS,gdseller/ShareJS,igmcdowell/ShareJS,modulexcite/ShareJS,rasata/ShareJS,erpframework/ShareJS,a0x/ShareJS,igmcdowell/ShareJS,share/ShareJS,mcanthony/ShareJS,freewind/ShareJS,matthewbauer/ShareJS,luto/ShareJS