Clean up build doc and coding guidelines.

doc/build.md

@@ -189,11 +189,11 @@ Test project /Users/sabrih/Desktop/workspace/build/Debug/plugin/al
 
 ##### Boost:
 
-Currently the Animal Logic plugin has a dependency on some of the boost components ( e.g thread ). When building Pixar USD, one needs to pass the following key,value paired arguments for boost to include those components: 
+Currently the Animal Logic plugin has a dependency on some of the boost components. When building Pixar USD, one needs to pass the following key,value paired arguments for boost to include those components: 
 e.g 
 
 ```
-python build_usd.py ~/Desktop/BUILD --build-args boost,"--with-date_time --with-thread" 
+python build_usd.py ~/Desktop/BUILD --build-args boost,"--with-date_time" 
 ```
 
 ***NOTE:*** ```--build-args``` needs to be passed at the very end of command, after build/install location.

doc/codingGuidelines.md

@@ -227,6 +227,8 @@ Our library currently has the following boost dependencies:
 ***Update:***
 * `boost::filesystem` and `boost::system` are removed. Until the transition to C++17 std::filesystem, [ghc::filesystem](https://github.com/gulrak/filesystem) must be used as an alternative across the project.
 
+* Dependency on `boost::thread` is removed from Animal Logic plugin.
+
 ## Modern C++
 Our goal is to develop [maya-usd](https://github.com/autodesk/maya-usd) following modern C++ practices. We’ll follow the [C++ Core Guidelines](http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines) and pay attention to:
 * `using` (vs `typedef`) keyword

plugin/al/lib/AL_USDMaya/CMakeLists.txt

@@ -171,8 +171,6 @@ target_compile_definitions(${LIBRARY_NAME}
         AL_MAYA_MACROS_EXPORT
         AL_USDMAYA_EXPORT
         AL_USDMAYA_LOCATION_NAME="${AL_USDMAYA_LOCATION_NAME}"
-        # Prevent link dependency on the Boost::System on MacOS
-        $<$<BOOL:${IS_MACOSX}>:BOOST_SYSTEM_NO_DEPRECATED>
 )
 
 target_include_directories(