old_contents: Import('env')
  env.Append(CXXFLAGS=["-std=c++11"], CPPPATH=["src/wakaama", "wakaama"])
  
new_contents: Import('env')
  env.Append(CFLAGS=["-std=gnu11"], CXXFLAGS=["-std=c++11"], CPPPATH=["src/wakaama", "wakaama"])
  
subject: Make C11 default. pio should actually do this.