Only replace opposite feedback if it's positive or negative
Only replace opposite feedback if it's positive or negative

Fixes #182

SulphurDioxide/metasmoke,j-f1/forked-metasmoke,angussidney/metasmoke,j-f1/forked-metasmoke,SulphurDioxide/metasmoke,angussidney/metasmoke,Charcoal-SE/metasmoke,Charcoal-SE/metasmoke,Charcoal-SE/metasmoke,Charcoal-SE/metasmoke,j-f1/forked-metasmoke,angussidney/metasmoke,j-f1/forked-metasmoke,SulphurDioxide/metasmoke,angussidney/metasmoke