misc: README direct to website for dependencies

This patch updates the README to direct the user to the appropriate
sections on the gem5.org website rather than duplicating information.

README

@@ -1,54 +1,29 @@
 This is the gem5 simulator.
 
-For detailed information about building the simulator and getting
+The main website can be found at http://www.gem5.org
-started please refer to:
-* The main website:     http://www.gem5.org
-* Documentation wiki:   http://www.gem5.org/Documentation 
-* Doxygen generated:    http://www.gem5.org/docs
-* Tutorials:            http://www.gem5.org/Tutorials
 
+A good starting point is http://www.gem5.org/Introduction, and for
+more information about building the simulator and getting started
+please see http://www.gem5.org/Documentation and
+http://www.gem5.org/Tutorials.
 
-Specific pages of interest are:
+To build gem5, you will need the following software: g++ or clang,
-http://www.gem5.org/Introduction
+Python (gem5 links in the Python interpreter), SCons, SWIG, zlib, m4,
-http://www.gem5.org/Build_System
+and lastly protobuf if you want trace capture and playback
-http://www.gem5.org/Dependencies
+support. Please see http://www.gem5.org/Dependencies for more details
-http://www.gem5.org/Running_gem5
+concerning the minimum versions of the aforementioned tools.
 
-Short version:
+Once you have all dependencies resolved, type 'scons
-External tools and required versions
+build/<ARCH>/gem5.opt' where ARCH is one of ALPHA, ARM, NULL, MIPS,
+POWER, SPARC, or X86. This will build an optimized version of the gem5
+binary (gem5.opt) for the the specified architecture. See
+http://www.gem5.org/Build_System for more details and options.
 
-To build gem5, you will need the following software:
+With the simulator built, have a look at
-g++ version 4.3 or newer.
+http://www.gem5.org/Running_gem5 for more information on how to use
-Python, version 2.4 - 2.7 (we don't support Python 3.X). gem5 links in the 
+gem5.
-    Python interpreter, so you need the Python header files and shared 
-    library (e.g., /usr/lib/libpython2.4.so) in addition to the interpreter
-    executable. These may or may not be installed by default. For example,
-    on Debian/Ubuntu, you need the "python-dev" package in addition to the
-    "python" package. If you need a newer or different Python installation
-     but can't or don't want to upgrade the default Python on your system,
-     see http://www.gem5.org/Using_a_non-default_Python_installation
-SCons, version 0.98.1 or newer. SCons is a powerful replacement for make. 
-    If you don't have administrator privileges on your machine, you can use the
-    "scons-local" package to install scons in your m5 directory, or install SCons
-    in your home directory using the '--prefix=' option.  
-SWIG, version 1.3.34 or newer
-zlib, any recent version. For Debian/Ubuntu, you will need the "zlib-dev" or
-    "zlib1g-dev" package to get the zlib.h header file as well as the library
-    itself.
-m4, the macro processor.
-
-
-4. In this directory, type 'scons build/<ARCH>/gem5.opt' where ARCH is one
-of ALPHA, ARM, MIPS, POWER, SPARC, or X86. This will build an optimized version
-of the gem5 binary (gem5.opt) for the the specified architecture.
-
-If you have questions, please send mail to gem5-users@gem5.org
-
-WHAT'S INCLUDED (AND NOT)
--------------------------
 
 The basic source release includes these subdirectories:
- - gem5:
    - configs: example simulation configuration scripts
    - ext: less-common external packages needed to build gem5
    - src: source code of the gem5 simulator
@@ -57,5 +32,10 @@ The basic source release includes these subdirectories:
    - util: useful utility programs and files
 
 To run full-system simulations, you will need compiled system firmware
-(console and PALcode for Alpha), kernel binaries and one or more disk images. 
+(console and PALcode for Alpha), kernel binaries and one or more disk
-Please see the gem5 download page for these items at http://www.gem5.org/Download 
+images. Please see the gem5 download page for these items at
+http://www.gem5.org/Download
+
+If you have questions, please send mail to gem5-users@gem5.org
+
+Enjoy using gem5 and please share your modifications and extensions.