strnlen implementation
strnlen implementation

since there is no ets_strnlen, provide an implementation

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