gnu: Add python-genshi.

* gnu/packages/python.scm (python-genshi, python2-genshi): New variables.
 * gnu/packages/patches/python-genshi-add-support-for-python-3.4-AST.patch: New file.
 * gnu/packages/patches/python-genshi-buildable-on-python-2.7.patch: New file.
 * gnu/packages/patches/python-genshi-disable-speedups-on-python-3.3.patch: New file.
 * gnu/packages/patches/python-genshi-fix-tests-on-python-3.5.patch: New file.
 * gnu/packages/patches/python-genshi-isstring-helper.patch: New file.
 * gnu/packages/patches/python-genshi-stripping-of-unsafe-script-tags.patch: New file.
 * gnu/local.mk (dist_patch_DATA): Add them.

Signed-off-by: Arun Isaac <arunisaac@systemreboot.net>

gnu/packages/patches/python-genshi-isstring-helper.patch

@@ -0,0 +1,37 @@
+From cc5e07284f44cdd9beec178c69070a53f55d1323 Mon Sep 17 00:00:00 2001
+From: Simon Cross <hodgestar@gmail.com>
+Date: Sun, 16 Feb 2014 18:43:20 +0000
+Subject: [PATCH 03/15] Add isstring helper.
+
+---
+ genshi/compat.py | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/genshi/compat.py b/genshi/compat.py
+index 9787325..6574e39 100644
+--- a/genshi/compat.py
++++ b/genshi/compat.py
+@@ -35,6 +35,15 @@ else:
+                 'Python 2 compatibility function. Not usable in Python 3.')
+ 
+ 
++# We need to test if an object is an instance of a string type in places
++
++if IS_PYTHON2:
++    def isstring(obj):
++        return isinstance(obj, basestring)
++else:
++    def isstring(obj):
++        return isinstance(obj, str)
++
+ # We need to differentiate between StringIO and BytesIO in places
+ 
+ if IS_PYTHON2:
+@@ -112,4 +121,3 @@ except NameError:
+             if not x:
+                 return False
+         return True
+-
+-- 
+2.12.0
+