Update the installation page by mentioning a 'system wide' rocksdb installation.

docs/installation.rst

@@ -6,30 +6,50 @@ Installing
 Building rocksdb
 ----------------
 
-Briefly describes how to build rocksdb under a ordinary debian/ubuntu.
-For more details consider https://github.com/facebook/rocksdb/blob/master/INSTALL.md::
+Briefly describes how to build rocksdb under an ordinary debian/ubuntu.
+For more details consider https://github.com/facebook/rocksdb/blob/master/INSTALL.md
 
-    $ apt-get install build-essential
-    $ apt-get install libsnappy-dev zlib1g-dev libbz2-dev libgflags-dev
-    $ git clone https://github.com/facebook/rocksdb.git
-    $ cd rocksdb
-    $ make shared_lib
+.. code-block:: bash
+
+    apt-get install build-essential
+    apt-get install libsnappy-dev zlib1g-dev libbz2-dev libgflags-dev
+    git clone https://github.com/facebook/rocksdb.git
+    cd rocksdb
+    make shared_lib
+
+
+Systemwide rocksdb
+^^^^^^^^^^^^^^^^^^
+The following command installs the shared library in ``/usr/lib/`` and the
+header files in ``/usr/include/rocksdb/``::
+
+    make install-shared INSTALL_PATH=/usr
+
+To uninstall use::
+
+    make uninstall INSTALL_PATH=/usr
+
+Local rocksdb
+^^^^^^^^^^^^^
+If you don't like the system wide installation, or you don't have the
+permissions, it is possible to set the following environment variables.
+These varialbes are picked up by the compiler, linker and loader
+
+.. code-block:: bash
 
-If you do not want to call ``make install`` export the following enviroment
-variables::
+    export CPLUS_INCLUDE_PATH=${CPLUS_INCLUDE_PATH}:`pwd`/include
+    export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:`pwd`
+    export LIBRARY_PATH=${LIBRARY_PATH}:`pwd`
 
-    $ export CPLUS_INCLUDE_PATH=${CPLUS_INCLUDE_PATH}:`pwd`/include
-    $ export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:`pwd`
-    $ export LIBRARY_PATH=${LIBRARY_PATH}:`pwd`
 
 Building pyrocksdb
 ------------------
 
 .. code-block:: bash
 
-    $ apt-get install python-virtualenv python-dev
-    $ virtualenv pyrocks_test
-    $ cd pyrocks_test
-    $ . bin/active
-    $ pip install "Cython>=0.20"
-    $ pip install git+git://github.com/stephan-hof/pyrocksdb.git
+    apt-get install python-virtualenv python-dev
+    virtualenv pyrocks_test
+    cd pyrocks_test
+    . bin/active
+    pip install "Cython>=0.20"
+    pip install git+git://github.com/stephan-hof/pyrocksdb.git