clarify python version

Author: Richard Jones

doc/announcement.txt

@@ -24,7 +24,7 @@ Though some new features made it in also:
 If you're upgrading from an older version of Roundup you *must* follow
 the "Software Upgrade" guidelines given in the maintenance documentation.
 
-Roundup requires python 2.3 or later for correct operation.
+Roundup requires python 2.3 or later (but not 3+) for correct operation.
 
 To give Roundup a try, just download (see below), unpack and run::
 
@@ -58,9 +58,9 @@ Roundup manages a number of issues (with flexible properties such as
 The system will facilitate communication among the participants by managing
 discussions and notifying interested parties when issues are edited. One of
 the major design goals for Roundup that it be simple to get going. Roundup
-is therefore usable "out of the box" with any python 2.3+ installation. It
-doesn't even need to be "installed" to be operational, though a
-disutils-based install script is provided.
+is therefore usable "out of the box" with any python 2.3+ (but not 3+)
+installation. It doesn't even need to be "installed" to be operational,
+though an install script is provided.
 
 It comes with two issue tracker templates (a classic bug/feature tracker and
 a minimal skeleton) and four database back-ends (anydbm, sqlite, mysql

doc/features.txt

@@ -12,7 +12,7 @@ from Ka-Ping Yee in the Software Carpentry "Track" design competition.
  - two templates included in the distribution for you to base your tracker on
  - play with the demo, customise it and then use *it* as the template for
    your production tracker
- - requires *no* additional support software - python (2.3+) is
+ - requires *no* additional support software - python (2.3+ but not 3+) is
    enough to get you going
  - easy to set up higher-performance storage backends like sqlite_,
    mysql_ and postgresql_

doc/installation.txt

@@ -30,8 +30,8 @@ Roundup scripts
 Prerequisites
 =============
 
-Roundup requires Python 2.3 or newer with a functioning anydbm
-module. Download the latest version from http://www.python.org/.
+Roundup requires Python 2.3 or newer (but not Python 3) with a functioning
+anydbm module. Download the latest version from http://www.python.org/.
 It is highly recommended that users install the latest patch version
 of python as these contain many fixes to serious bugs.
 

setup.py

@@ -116,7 +116,7 @@ def main():
 If you're upgrading from an older version of Roundup you *must* follow
 the "Software Upgrade" guidelines given in the maintenance documentation.
 
-Roundup requires python 2.3 or later for correct operation.
+Roundup requires python 2.3 or later (but not 3+) for correct operation.
 
 To give Roundup a try, just download (see below), unpack and run::
 
@@ -147,9 +147,9 @@ def main():
 The system will facilitate communication among the participants by managing
 discussions and notifying interested parties when issues are edited. One of
 the major design goals for Roundup that it be simple to get going. Roundup
-is therefore usable "out of the box" with any python 2.3+ installation. It
-doesn't even need to be "installed" to be operational, though a
-disutils-based install script is provided.
+is therefore usable "out of the box" with any python 2.3+ (but not 3+)
+installation. It doesn't even need to be "installed" to be operational,
+though an install script is provided.
 
 It comes with two issue tracker templates (a classic bug/feature tracker and
 a minimal skeleton) and five database back-ends (anydbm, sqlite, metakit,