Update the docs explaining how to build an SDK.

Change-Id: Ibb2ddb751ac6779b6bbbbcf4cb610d4d86280fee

docs/howto_SDK_git_cygwin.txt

@@ -16,6 +16,7 @@ limitations under the License.
 Subject: How to get the android source code using Cygwin and Git
 Date:    2009/04/27
 Updated: 2009/05/21
+Updated: 2010/03/30
 
 
 Table of content:
@@ -33,15 +34,20 @@ This document explains how to checkout the Android source from the git
 repositories under Windows.
 
 As stated in development/docs/howto_build_SDK.txt, one can't build the whole
-Android source code under Windows. You can only build a the SDK tools for
+Android source code under Windows. You can only build the SDK tools for
 Windows.
 
 There are a number of caveats in checking out the code from Git under Windows. 
 This document tries to explain them.
 
 First you will need to meet the following requirements:
-- You must have Cygwin installed.
-  See http://www.cygwin.com/
+- You must have Cygwin installed. But wait! You CANNOT use the latest Cygwin 1.7.
+  Instead you MUST use the "legacy Cygwin 1.5" that you can find at this page:
+
+    http://cygwin.org/win-9x.html
+
+  Don't mind the page title, just grab setup-legacy.exe and it will works just fine
+  under XP or Vista.
 
 - You must install Cyginw using the "Unix / Binary" mode.
   If you don't do that, git will fail to properly compute some SHA1 keys.
@@ -51,6 +57,9 @@ First you will need to meet the following requirements:
 
   Note: if you want to build the SDK, check the howto_build_SDK.txt file
   for a list of extra required packages.
+  The short summary is that you need at least these:
+    autoconf, bison, curl, flex, gcc, g++, git, gnupg, make, mingw-zlib, python, unzip, zip
+  and you must avoid the "readline" package.
 
 
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