README: further clarity about when you need to acquire source and when you don't

README

@@ -182,6 +182,8 @@ easy_install Way, and The Running-In-Place Way.  Choose one:
   top-level tahoe directory (replacing the word DIST with etch, dapper, edgy,
   or feisty as appropriate).
 
+  Get the source code (see above).
+
   If you're running on a debian system, run 'make deb-etch', 'make deb-sid',
   'make deb-edgy', or 'make deb-feisty' from within the tahoe top-level
   directory to construct a debian package named 'allmydata-tahoe' which you
@@ -189,9 +191,11 @@ easy_install Way, and The Running-In-Place Way.  Choose one:
 
  The Setuptools Way:
 
-  Just run 'python setup.py install'. This will compile and install the Tahoe
-  code to the standard location for your operating system (on unix, that is
-  somewhere inside /usr/lib/). It will also acquire and install the 
+  Get the source code (see above).
+
+  Run 'python setup.py install'. This will compile and install the Tahoe code
+  to the standard location for your operating system (on unix, that is
+  somewhere inside /usr/lib/). It will also acquire and install the
   easy_install-able dependencies (zfec, foolscap, simplejson, nevow, and if
   on Windows pywin32) to the same place.
 
@@ -201,6 +205,8 @@ easy_install Way, and The Running-In-Place Way.  Choose one:
 
  The easy_install Way:
 
+  You don't need to download the source code first.
+
   Tahoe is registered with the Python Package Index (PyPI), so the
   'easy_install' tool can download and install it for you. Just type
   'easy_install allmydata-tahoe' from any shell. That will download the most
@@ -212,6 +218,8 @@ easy_install Way, and The Running-In-Place Way.  Choose one:
 
  The Running-In-Place Way:
 
+  Get the source code (see above).
+
   You can use Tahoe without installing it. Once you've built Tahoe then you
   can execute "./bin/allmydata-tahoe". (When the allmydata-tahoe script is in
   an Tahoe source distribution, it adds the necessary directory to the Python