cpu/esp8266: cpu configuration tuned
cpu/esp8266: cpu configuration tuned

With the new ETS task handling thread, the stack sizes could be down sized.
basilfx/RIOT,authmillenon/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,BytesGalore/RIOT,josephnoir/RIOT,jasonatran/RIOT,yogo1212/RIOT,basilfx/RIOT,A-Paul/RIOT,authmillenon/RIOT,x3ro/RIOT,authmillenon/RIOT,aeneby/RIOT,rfuentess/RIOT,jasonatran/RIOT,OTAkeys/RIOT,toonst/RIOT,authmillenon/RIOT,jasonatran/RIOT,BytesGalore/RIOT,cladmi/RIOT,ant9000/RIOT,aeneby/RIOT,rfuentess/RIOT,x3ro/RIOT,ant9000/RIOT,rfuentess/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,mtausig/RIOT,ant9000/RIOT,ant9000/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,kaspar030/RIOT,BytesGalore/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,mfrey/RIOT,BytesGalore/RIOT,mfrey/RIOT,basilfx/RIOT,A-Paul/RIOT,rfuentess/RIOT,toonst/RIOT,yogo1212/RIOT,mtausig/RIOT,miri64/RIOT,BytesGalore/RIOT,OTAkeys/RIOT,aeneby/RIOT,kaspar030/RIOT,basilfx/RIOT,jasonatran/RIOT,mtausig/RIOT,toonst/RIOT,A-Paul/RIOT,kYc0o/RIOT,authmillenon/RIOT,smlng/RIOT,x3ro/RIOT,lazytech-org/RIOT,smlng/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,smlng/RIOT,yogo1212/RIOT,lazytech-org/RIOT,cladmi/RIOT,A-Paul/RIOT,yogo1212/RIOT,basilfx/RIOT,cladmi/RIOT,mtausig/RIOT,yogo1212/RIOT,rfuentess/RIOT,kaspar030/RIOT,A-Paul/RIOT,cladmi/RIOT,miri64/RIOT,RIOT-OS/RIOT,miri64/RIOT,aeneby/RIOT,cladmi/RIOT,lazytech-org/RIOT,OTAkeys/RIOT,aeneby/RIOT,mfrey/RIOT,toonst/RIOT,kYc0o/RIOT,jasonatran/RIOT,mfrey/RIOT,smlng/RIOT,RIOT-OS/RIOT,mtausig/RIOT,kaspar030/RIOT,miri64/RIOT,x3ro/RIOT,josephnoir/RIOT,lazytech-org/RIOT,josephnoir/RIOT,smlng/RIOT,ant9000/RIOT,josephnoir/RIOT,OTAkeys/RIOT,kaspar030/RIOT,x3ro/RIOT,miri64/RIOT,OTAkeys/RIOT,kYc0o/RIOT,mfrey/RIOT,toonst/RIOT,lazytech-org/RIOT,kYc0o/RIOT,yogo1212/RIOT,josephnoir/RIOT