configure: require python mako module

It is now a hard dependency because of the autogeneration of
format pack and unpack functions.

Update the documentation to reflect this change.

v2:
- Inline python script in m4 file and use PYTHON2

v3:

- Remove semicolons and quotes and change coding style
- Add Ilia Mirkin suggestion to use Python's split functionality.
- Use AX_CHECK_PYTHON_MAKO_MODULE name.
- Change to MIT license

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
diff --git a/docs/install.html b/docs/install.html
index f12425f..b12e1cb 100644
--- a/docs/install.html
+++ b/docs/install.html
@@ -38,6 +38,10 @@
 Version 2.6.4 or later should work.
 </li>
 <br>
+<li><a href="http://www.makotemplates.org/">Python Mako module</a> -
+Python Mako module is required. Version 0.7.3 or later should work.
+</li>
+</br>
 <li><a href="http://www.scons.org/">SCons</a> is required for building on
 Windows and optional for Linux (it's an alternative to autoconf/automake.)
 </li>
@@ -78,7 +82,7 @@
 <pre>
   sudo yum install flex bison imake libtool xorg-x11-proto-devel libdrm-devel \
   gcc-c++ xorg-x11-server-devel libXi-devel libXmu-devel libXdamage-devel git \
-  expat-devel llvm-devel
+  expat-devel llvm-devel python-mako
 </pre>