update build/install instructions

xwords4/android/INSTALL.txt

@@ -1,19 +1,29 @@
 Here's how I'm building crosswords for Android.
 
-First, the build process requires a file called local.properties that
-must be generated locally.  Generate it before your first build by
-running ./scripts/setup_local_props.sh.
+First, cd into the directory xwords4/android/XWords4. Everything
+happens there.
 
-The working directory is XWords4 within this (android/) directory.
-Run the following commands from there.
+IF (and it's a big if) you have all the necessary tools installed (the
+Android SDK and NDK, apache ant, and probably other stuff I've
+forgotten), two commands will build it, the first a one-time deal and
+the second repeated every time you made a change.
 
-Build the jni library (the cross-platform code):
-# ../scripts/ndkbuild.sh 
+The build process requires a file called local.properties that must be
+generated locally.  Generate it before your first build by running
+
+# ../scripts/setup_local_props.sh 
+
+Then build using this command:
+
+# ant debug 
+
+Or, if you have a device or emulator attached (listed by 'adb
+devices'), try
 
-Then build the app for the emulator (assuming it's running)
 # ant debug install
 
-Build for a device (requires you've set up your keys.  I did this too
-long ago to remember how but the info's easy to find):
-# ant release
-(The above command not yet verified for new SDK I installed on 11/19/11)
+Making a release build requires that you've set up your keys.  (I did
+this too long ago to remember how but the info's easy to find).  Once
+that's done, just tether your device and type
+
+# ant release install