docs: Update documentation to include solution to potential problems with gtk module on OS X

Change-Id: Ib6a46b64bff07c3aa3e799a7490b45ba22fa4c4f
diff --git a/docs/source/faq.rst b/docs/source/faq.rst
index cad083a..71cb2cb 100644
--- a/docs/source/faq.rst
+++ b/docs/source/faq.rst
@@ -138,6 +138,26 @@
 Something is wrong with your python bindings and python bindings dependencies.  Please follow
 the :ref:`requirements` section that lists what should be installed in order to run visualizer.
 
+.. _Problems with the gtk python module on OS X:
+
+Problems with the gtk python module on OS X
+-------------------------------------------
+
+.. topic:: ./waf configure got stuck during the gtk module check
+
+    When running ``./waf configure``, the process freezes at the stage of detecting gtk module::
+
+      ...
+      Checking for 'sqlite3'                                         : yes
+      Checking for header linux/if_tun.h                             : not found
+      Checking for python module 'gtk'                               :
+
+If ``./waf configure`` on OSX got stuck during the gtk python module check, it most likely
+means that something is wrong with X11 required by this module.  You can try to reinstall X11
+(`XQuartz <http://xquartz.macosforge.org>`_) or configure NS-3 without python bindings (``./waf
+configure --disable-python``).  Note that disabling python bindings will also disable the
+visualizer module.
+
 Code questions
 --------------
 
diff --git a/docs/source/getting-started.rst b/docs/source/getting-started.rst
index 7d3e927..5f005e7 100644
--- a/docs/source/getting-started.rst
+++ b/docs/source/getting-started.rst
@@ -40,13 +40,13 @@
 .. role:: red
 
 .. note::
-   :red:`!!! ndnSIM requires boost version at least 1.49.` Many linux distribution
+   :red:`ndnSIM requires boost version at least 1.49.` Many linux distribution
    (Fedora 16, 17 at the time of this writing) ship an old version of boost, making it
    impossible to compile ndnSIM out-of-the-box.  Please install the latest version, following
    :ref:`these simple instructions <Installing boost libraries>`.
 
 .. note::
-   !!! If you do not have root permissions to install boost, you can install it in your home
+   If you do not have root permissions to install boost, you can install it in your home
    folder.  However, you need to be make sure that `libboost_iostreams` library is successfully
    compiled and is installed.  Please refer to :ref:`the following example <Installing boost
    libraries>` for the hints how to successfully compile and install boost libraries on Ubuntu
@@ -169,6 +169,12 @@
         # or run ``sudo port select python python27``
         ./waf
 
+    .. note::
+        On OS X configuration stage may get :ref:`stuck at detecting gtk module <Problems with
+        the gtk python module on OS X>`.  Make sure you have `XQuartz
+        <http://xquartz.macosforge.org>`_ installed or disable python as described in the
+        following instructions.
+
     Python bindings is an optional and not very stable feature of NS-3 simulator.  It is
     possible to disable python bindings compilation either to speed up compilation or to avoid
     certain compilation errors (e.g., "Could not find a task generator for the name
@@ -195,7 +201,7 @@
 
         ./waf --run=ndn-simple
 
-    To run ``ndn-grid.cpp` scenario:
+    To run ``ndn-grid.cpp`` scenario:
 
     .. code-block:: bash