[glom] configure.ac: Require python 3.

[Murray Cumming <murrayc src gnome org>]

commit 4e81192d86592e0fd7383fd1fa53d4f947a7bcce
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Jul 13 09:57:34 2015 +0200

    configure.ac: Require python 3.
    
    It's now on all the distros.

 configure.ac |    8 ++------
 1 files changed, 2 insertions(+), 6 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index d377e93..f530e74 100644
--- a/configure.ac
+++ b/configure.ac
@@ -233,14 +233,10 @@ AC_CHECK_FUNCS([strptime])
 AM_PATH_PYTHON
 
 # Get the compiler and linker flags for embedding Python.
-# To specify a particular python version you must set an environment variable.
-# For instance:
-#   export PYTHON=python3.3
-# When using jhbuild, note that you will need to do that before starting jhbuild,
-# so that jhbuild sets PYTHONPATH correctly.
+# To specify a particular python version you must pass PYTHON_VERSION.
+# For instance, ./configure PYTHON_VERSION="3.4" --prefix=/opt/gnome
 # 
 # See http://www.gnu.org/software/autoconf-archive/ax_python_devel.html
-# TODO: Use AX_PYTHON_DEVEL(>= '3.0.0') when we can make the build use the python3 version of boost-python 
by default.
 AX_PYTHON_DEVEL([>= '3.0.0'])
 
 # Get the CFLAGS and LIBS for boost::python.