Fix cbuf::read and cbuf::peak return types
Fix cbuf::read and cbuf::peak return types

Fixes #12

chrisfraser/Arduino,martinayotte/ESP8266-Arduino,chrisfraser/Arduino,jes/Arduino,CanTireInnovations/Arduino,Links2004/Arduino,martinayotte/ESP8266-Arduino,gguuss/Arduino,gguuss/Arduino,Adam5Wu/Arduino,jes/Arduino,hallard/Arduino,Cloudino/Arduino,Cloudino/Cloudino-Arduino-IDE,NextDevBoard/Arduino,KaloNK/Arduino,toastedcode/esp8266-Arduino,wemos/Arduino,Links2004/Arduino,wemos/Arduino,NextDevBoard/Arduino,quertenmont/Arduino,chrisfraser/Arduino,NullMedia/Arduino,jes/Arduino,Lan-Hekary/Arduino,CanTireInnovations/Arduino,Juppit/Arduino,me-no-dev/Arduino,jes/Arduino,edog1973/Arduino,toastedcode/esp8266-Arduino,me-no-dev/Arduino,Adam5Wu/Arduino,quertenmont/Arduino,Juppit/Arduino,Juppit/Arduino,Cloudino/Cloudino-Arduino-IDE,Lan-Hekary/Arduino,chrisfraser/Arduino,NullMedia/Arduino,wemos/Arduino,sticilface/Arduino,CanTireInnovations/Arduino,Cloudino/Arduino,quertenmont/Arduino,Links2004/Arduino,Adam5Wu/Arduino,Cloudino/Arduino,esp8266/Arduino,martinayotte/ESP8266-Arduino,Lan-Hekary/Arduino,chrisfraser/Arduino,sticilface/Arduino,me-no-dev/Arduino,Adam5Wu/Arduino,toastedcode/esp8266-Arduino,CanTireInnovations/Arduino,toastedcode/esp8266-Arduino,lrmoreno007/Arduino,lrmoreno007/Arduino,gguuss/Arduino,me-no-dev/Arduino,KaloNK/Arduino,NullMedia/Arduino,esp8266/Arduino,Links2004/Arduino,hallard/Arduino,Links2004/Arduino,hallard/Arduino,NextDevBoard/Arduino,gguuss/Arduino,esp8266/Arduino,Cloudino/Arduino,wemos/Arduino,Cloudino/Cloudino-Arduino-IDE,martinayotte/ESP8266-Arduino,NullMedia/Arduino,Juppit/Arduino,CanTireInnovations/Arduino,KaloNK/Arduino,edog1973/Arduino,Cloudino/Arduino,Cloudino/Cloudino-Arduino-IDE,quertenmont/Arduino,lrmoreno007/Arduino,jes/Arduino,Cloudino/Arduino,NextDevBoard/Arduino,esp8266/Arduino,CanTireInnovations/Arduino,hallard/Arduino,Cloudino/Cloudino-Arduino-IDE,Lan-Hekary/Arduino,sticilface/Arduino,me-no-dev/Arduino,martinayotte/ESP8266-Arduino,sticilface/Arduino,edog1973/Arduino,NextDevBoard/Arduino,CanTireInnovations/Arduino,edog1973/Arduino,edog1973/Arduino,esp8266/Arduino,toastedcode/esp8266-Arduino,sticilface/Arduino,lrmoreno007/Arduino,Adam5Wu/Arduino,gguuss/Arduino,Cloudino/Arduino,KaloNK/Arduino,Cloudino/Cloudino-Arduino-IDE,NullMedia/Arduino,KaloNK/Arduino,Juppit/Arduino,Lan-Hekary/Arduino,wemos/Arduino,lrmoreno007/Arduino,quertenmont/Arduino,hallard/Arduino,Cloudino/Cloudino-Arduino-IDE