fix a bug when readline from uart
Merge pull request #51 from nodemcu/dev094

fix a bug when readline from uart
build latest firmware, add pre_build/latest folder
build latest firmware, add pre_build/latest folder
replace custom stdarg.h header file with the one in toolchain
Merge pull request #52 from nodemcu/dev094

replace custom stdarg.h header file with the one in gcc toolchain
Merge pull request #1 from nodemcu/master

update