README.md: Remove special-api build status and document dist.sh --help
README.md: Remove special-api build status and document dist.sh --help

zolkis/iotivity-node,zqzhang/iotivity-node,zolkis/iotivity-node,zqzhang/iotivity-node,zolkis/iotivity-node,zqzhang/iotivity-node,zolkis/iotivity-node,zqzhang/iotivity-node,zolkis/iotivity-node,zqzhang/iotivity-node