Rollup merge of #23836 - Hoverbear:patch-1, r=steveklabnik
Rollup merge of #23836 - Hoverbear:patch-1, r=steveklabnik

To not use `old_io` and `os`, which are deprecated. Since there is no more `MemoryMap` used byte parsing instead to generate the second potential error.

You can see the code working fine [here](http://is.gd/4g0wwp) on the PlayPen.

omasanori/rust,jroesch/rust,TheNeikos/rust,krzysz00/rust,andars/rust,pshc/rust,mdinger/rust,vhbit/rust,andars/rust,aneeshusa/rust,kwantam/rust,omasanori/rust,rohitjoshi/rust,gifnksm/rust,mihneadb/rust,aidancully/rust,ejjeong/rust,zubron/rust,dwillmer/rust,zachwick/rust,vhbit/rust,cllns/rust,carols10cents/rust,ruud-v-a/rust,aidancully/rust,miniupnp/rust,rohitjoshi/rust,nwin/rust,KokaKiwi/rust,graydon/rust,sae-bom/rust,aepsil0n/rust,reem/rust,robertg/rust,andars/rust,cllns/rust,aepsil0n/rust,jroesch/rust,zachwick/rust,omasanori/rust,l0kod/rust,krzysz00/rust,ebfull/rust,miniupnp/rust,jashank/rust,mdinger/rust,gifnksm/rust,pelmers/rust,ejjeong/rust,graydon/rust,GBGamer/rust,cllns/rust,carols10cents/rust,mdinger/rust,vhbit/rust,krzysz00/rust,zubron/rust,TheNeikos/rust,mihneadb/rust,ruud-v-a/rust,philyoon/rust,dwillmer/rust,carols10cents/rust,l0kod/rust,ebfull/rust,pshc/rust,aneeshusa/rust,jashank/rust,zachwick/rust,l0kod/rust,pshc/rust,GBGamer/rust,jroesch/rust,ruud-v-a/rust,kwantam/rust,zachwick/rust,reem/rust,mdinger/rust,mvdnes/rust,nwin/rust,omasanori/rust,jashank/rust,zubron/rust,zubron/rust,TheNeikos/rust,andars/rust,carols10cents/rust,jroesch/rust,graydon/rust,robertg/rust,reem/rust,mvdnes/rust,pshc/rust,seanrivera/rust,sae-bom/rust,graydon/rust,zubron/rust,mdinger/rust,aidancully/rust,gifnksm/rust,rohitjoshi/rust,rohitjoshi/rust,avdi/rust,seanrivera/rust,zaeleus/rust,omasanori/rust,aidancully/rust,nwin/rust,graydon/rust,rohitjoshi/rust,avdi/rust,cllns/rust,miniupnp/rust,zachwick/rust,seanrivera/rust,philyoon/rust,zubron/rust,victorvde/rust,avdi/rust,sae-bom/rust,zubron/rust,omasanori/rust,ebfull/rust,reem/rust,mvdnes/rust,aidancully/rust,miniupnp/rust,zaeleus/rust,jroesch/rust,gifnksm/rust,nwin/rust,mihneadb/rust,dwillmer/rust,nwin/rust,GBGamer/rust,vhbit/rust,KokaKiwi/rust,nwin/rust,pelmers/rust,graydon/rust,jashank/rust,philyoon/rust,dwillmer/rust,pelmers/rust,pshc/rust,krzysz00/rust,KokaKiwi/rust,jashank/rust,ejjeong/rust,jashank/rust,seanrivera/rust,jashank/rust,dwillmer/rust,mvdnes/rust,l0kod/rust,aneeshusa/rust,gifnksm/rust,cllns/rust,jroesch/rust,l0kod/rust,victorvde/rust,l0kod/rust,robertg/rust,l0kod/rust,GBGamer/rust,robertg/rust,mihneadb/rust,zachwick/rust,avdi/rust,nwin/rust,andars/rust,vhbit/rust,vhbit/rust,pshc/rust,XMPPwocky/rust,ejjeong/rust,avdi/rust,carols10cents/rust,zaeleus/rust,victorvde/rust,pshc/rust,aepsil0n/rust,nwin/rust,ebfull/rust,GBGamer/rust,ejjeong/rust,TheNeikos/rust,kwantam/rust,seanrivera/rust,gifnksm/rust,aneeshusa/rust,carols10cents/rust,philyoon/rust,mihneadb/rust,GBGamer/rust,dwillmer/rust,sae-bom/rust,TheNeikos/rust,vhbit/rust,sae-bom/rust,mihneadb/rust,mvdnes/rust,avdi/rust,robertg/rust,miniupnp/rust,XMPPwocky/rust,robertg/rust,KokaKiwi/rust,ruud-v-a/rust,GBGamer/rust,aidancully/rust,victorvde/rust,sae-bom/rust,pelmers/rust,dwillmer/rust,aepsil0n/rust,ebfull/rust,KokaKiwi/rust,victorvde/rust,kwantam/rust,pshc/rust,ruud-v-a/rust,philyoon/rust,miniupnp/rust,pelmers/rust,seanrivera/rust,krzysz00/rust,victorvde/rust,miniupnp/rust,XMPPwocky/rust,mdinger/rust,andars/rust,zaeleus/rust,XMPPwocky/rust,vhbit/rust,philyoon/rust,dwillmer/rust,KokaKiwi/rust,kwantam/rust,kwantam/rust,TheNeikos/rust,aepsil0n/rust,miniupnp/rust,zubron/rust,reem/rust,zaeleus/rust,rohitjoshi/rust,ruud-v-a/rust,jashank/rust,aneeshusa/rust,aepsil0n/rust,XMPPwocky/rust,jroesch/rust,l0kod/rust,jroesch/rust,reem/rust,krzysz00/rust,pelmers/rust,XMPPwocky/rust,zaeleus/rust,GBGamer/rust,ebfull/rust,mvdnes/rust,cllns/rust,aneeshusa/rust,ejjeong/rust