Update INSTALL file

INSTALL

@@ -1,19 +1,27 @@
 SUPERTUXKART INSTALLATION INSTRUCTIONS
 ======================================
 
-General
--------
+Note : If you obtained this source code from github, you also need to download the game assets from sourceforge using SVN.
+    svn checkout https://svn.code.sf.net/p/supertuxkart/code/stk-assets stk-assets
+Place the stk-assets folder next to the source root stk-code folder.
+See http://supertuxkart.sourceforge.net/Source_control for more information
+
+
+Building STK on Linux
+--------------------
 
 First, make sure that you have the following packages installed:
 
-  * OpenGL (or Mesa 3.0 or later)
+  * OpenGL (mesa)
   * OpenAL (recommended: openal-soft-devel)
   * Ogg    (libogg-dev)
   * Vorbis (libvorbis-dev)
   * libcurl (libcurl-devel)
   * libbluetooth (bluez-devel)
-  * fribidi (fribidi-devel) - optional for right-to-left text
 
+Ubuntu command :
+    sudo apt-get install autoconf automake build-essential cmake libogg-dev libvorbis-dev libopenal-dev libxxf86vm-dev libgl1-mesa-dev libglu1-mesa-dev libcurl4-openssl-dev libfribidi-dev libbluetooth-dev
+  
 Unpack the files from the tarball like this:
 
   tar xzf supertuxkart-*.tar.gz
@@ -21,9 +29,6 @@ Unpack the files from the tarball like this:
 
 where '*' is the version of SuperTuxkart you downloaded - eg 0.8.0. Then:
 
-* Build irrlicht (atm, this will be included in cmake soonish)
-  cd lib/irrlicht/source/Irrlicht
-  NDEBUG=1 make
 
 * Compile SuperTuxKart:
     mkdir cmake_build 
@@ -46,6 +51,7 @@ will be copied to /usr/local/bin. To change the default installation
 location, specify CMAKE_INSTALL_PREFIX when running cmake, e.g.:
   cmake .. -DCMAKE_INSTALL_PREFIX=/opt/stk
 
+  
 Building STK on OS X
 --------------------
 See http://supertuxkart.sourceforge.net/Building_and_packaging_on_OSX