Changed references to Python 1.5.2 to Python 2.1

doc/DEBUGGING.txt

@@ -27,7 +27,7 @@ Using the Medusa Monitor
      file) must be plain text, not encrypted.
 
   To use the monitor, start it from the shell prompt like so (as if
-  from the Zope root; must be python 1.5.2 or later):
+  from the Zope root):
 
   python ZServer/medusa/monitor_client.py localhost 8099
 

doc/INSTALL.txt

@@ -7,16 +7,16 @@ Building and installing Zope from source
 
 Important notes
 
-   ZOPE 2.0 REQUIRES PYTHON 1.5.2!
+   ZOPE 2.4 REQUIRES PYTHON 2.1!
 
-   See CHANGES.txt for important notes on Zope 2.0.
+   See CHANGES.txt for important notes on Zope 2.4.
 
 Quick Start
 
   If you are impatient, the following commands should get you up and
   running with Zope 2 using ZServer and ZODB 3 on Unix::
 
-    python w_pcgi.py  # Note, this must be Python 1.5.2
+    python w_pcgi.py  # Note, this must be Python 2.1
     ./start
 
   The first command builds and adjusts Zope.  Take note of the user

doc/LOGGING.txt

@@ -10,7 +10,7 @@ Zope Logging
  most easily by providing the settings on the z2.py command line.  For
  example::
 
-  $ python1.5.2 z2.py ZSYSLOG_SERVER="syslog.mydomain.com:514" \
+  $ python2.1 z2.py ZSYSLOG_SERVER="syslog.mydomain.com:514" \
      STUPID_LOG_FILE=var/Zope.log"
 
  Currently, the following environment variables can be set:

doc/WEBSERVER.txt

@@ -49,7 +49,7 @@ Using Zope in multi-threaded mode with ZServer
   'z2.py' startup script.  From the top level Zope directory, you
   can::
 
-    bash% python1.5.2 z2.py -p
+    bash% python2.1 z2.py -p
 
   Note, you must have gone through the directions in 'INSTALL.txt' for
   this to work.
@@ -60,7 +60,7 @@ Using Zope in multi-threaded mode with ZServer
   is not named 'Zope.cgi' and is not in the same directory as 'z2.py',
   then you can specify the file name after the '-p', like::
 
-    bash% python.1.5.2 z2.py -p /path/to/PCGI/resource/file
+    bash% python2.1 z2.py -p /path/to/PCGI/resource/file
 
   Now the Zope long running process is started up, and the PCGI
   component is loaded and ready to receive CGI requests from your