从CMake执行find_package(OpenSceneGraph REQUIRED COMPONENTS osgDB osgUtil)这句；情况如下；
当前OSG已经安装好；环境变量添加了OSG_ROOT（其值是OSG安装的根目录），并且 %OSG_ROOT%\bin 添加到了path；
有一个警告，已经done了；
Found osgDB: optimized;D:/OSGEarth/lib/osgDB.lib;debug;D:/OSGEarth/lib/osgDBd.lib
Found osgUtil: optimized;D:/OSGEarth/lib/osgUtil.lib;debug;D:/OSGEarth/lib/osgUtild.lib
......
For compatibility, CMake is ignoring the variable.
Call Stack (most recent call first):
CMakeLists.txt:4 (find_package)
This warning is for project developers. Use -Wno-dev to suppress it.
Found osg: optimized;D:/OSGEarth/lib/osg.lib;debug;D:/OSGEarth/lib/osgd.lib
Found OpenThreads: optimized;D:/OSGEarth/lib/OpenThreads.lib;debug;D:/OSGEarth/lib/OpenThreadsd.lib
Found OpenScen
