setup.py: keep Python 2.3 compatibility Though we only support Python 2.4 or greater, we should keep setup.py compatible with earlier versions on the syntactic level. Otherwise people will simply get a SyntaxError when trying to install Mercurial with an old version of Python. With this change, the setup.py file can be imported with Python 2.3 and we then issue a friendly error message when we detect that Python is too old.

Merge with stable

extensions help: make disabling example analogous to enabling example The example for enabling an extension in the module search path is: foo = foo can only be disabled by: foo = ! and not by: hgext.foo = ! As the examples now omit "hgext." the example hgext.bar = ! is misleading.