readme GNU toolchain not tested
roll back user_config.h:(
Fix the bug of memory release in documents.
Merge pull request #49 from nodemcu/dev094

fix file api issue when compile using gcc toolchain
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