[WEEX-433] [core] rm jni code from weexcore

[lucky-chen]

• rm jni code from weexcore
  • jni.h
  • bridge_impl_android.h
  • android/base/string/string_utils.h
  • android/base/log_utils.h
• edit cmake compile option
  • use set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11") to replace add_compile_options(-std=c++11) (see: https://blog.csdn.net/10km/article/details/51731959)
  • for wson error: invalid arguments "-std=c++11" not allowed with 'C

[weex-bot]

	Messages
📖	has no android file changed.
📖	android test finished.

Generated by 🚫 dangerJS