Adds installation instructions for log4cxx.

Windows and Mac require log4cxx to be installed via choco and brew,
respectively. This change updates the build and install instructions
to include information about installing log4cxx.

Author: nburek

source/Installation/OSX-Development-Setup.rst

@@ -59,6 +59,9 @@ You need the following things installed to build ROS 2:
 
        brew install opencv
 
+       # install dependencies for rcl_logging_log4cxx
+       brew install log4cxx
+
 #.
    Install rviz dependencies
 

source/Installation/OSX-Install-Binary.rst

@@ -69,6 +69,9 @@ You need the following things installed before installing ROS 2.
        # install Qt for RViz
        brew install qt freetype assimp
 
+       # install dependencies for rcl_logging_log4cxx
+       brew install log4cxx
+
 *
   Install rqt dependencies
 

source/Installation/Windows-Development-Setup.rst

@@ -302,7 +302,7 @@ Hit the windows key and type ``Edit Group Policy``. Navigate to Local Computer P
 
 Close and open your terminal to reset the environment and try building again.
 
-CMake Packages Unable to Find asio, tinyxml2, tinyxml, or eigen
+CMake Packages Unable to Find asio, tinyxml2, tinyxml, eigen, or log4cxx
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 We've seen, but been unable to identify the root cause, that sometimes the chocolatey packages for ``asio``, ``tinyxml2``, etc. do not add important registry entries and that will cause CMake to be unable to find them when building ROS 2.

source/Installation/Windows-Install-Binary.rst

@@ -171,12 +171,13 @@ Please download these packages from `this <https://github.com/ros2/choco-package
 * eigen-3.3.4.nupkg
 * tinyxml-usestl.2.6.2.nupkg
 * tinyxml2.6.0.0.nupkg
+* log4cxx.0.10.0.nupkg
 
 Once these packages are downloaded, open an administrative shell and execute the following command:
 
 .. code-block:: bash
 
-   > choco install -y -s <PATH\TO\DOWNLOADS\> asio eigen tinyxml-usestl tinyxml2
+   > choco install -y -s <PATH\TO\DOWNLOADS\> asio eigen tinyxml-usestl tinyxml2 log4cxx
 
 Please replace ``<PATH\TO\DOWNLOADS>`` with the folder you downloaded the packages to.