feature:

1.Add spdlog to save log file
2.Add program options to connect specific broadcast code and decide whether to save log file
3.Add comments in readme for windows 64-bit project compilation

LICENSE.txt

@@ -1,4 +1,4 @@
-The following portions of the LIVOX’s Livox SDK (“Software” referred to in the terms below) are made available to you under the terms of the MIT License provided below.  
+The following portions of the LIVOX’s Livox SDK (“Software” referred to in the terms below) are made available to you under the terms of the MIT License provided below.  
 
 Livox-SDK
 ├── CMakeLists.txt
@@ -25,6 +25,7 @@ Livox-SDK
         │   ├── io_thread.cpp
         │   ├── io_thread.h
         │   ├── logging.h
+        │   ├── logging.cpp
         │   ├── network_util.cpp
         │   ├── network_util.h
         │   ├── noncopyable.h
@@ -675,4 +676,27 @@ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+===============================================================
+LIVOX’s Livox SDK uses unmodified libraries of spdlog(https://github.com/gabime/spdlog), which is licensed under MIT license. A copy of the MIT license is provided below and is also available at https://github.com/gabime/spdlog/blob/v1.x/LICENSE.
 
+The MIT License (MIT)
+
+Copyright (c) 2016 Gabi Melman.                                       
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.