Fixed a compatibility bug for Python 3 by adding xrange to

compat.py.

The code in tablib/formats/_xls.py used xrange in parsing excel spreadsheets.
xrange is not a builtin for Python 3, so I've added
	xrange = range
in compat.py and imported it in tablib/formats/_xls.py.

AUTHORS

@@ -28,3 +28,4 @@ Patches and Suggestions
 - Marc Abramowitz
 - Alex Gaynor
 - James Douglass
+- Tommy Anthony

tablib/compat.py

@@ -37,6 +37,7 @@ if is_py3:
     unicode = str
     bytes = bytes
     basestring = str
+    xrange = range
 
 else:
     from cStringIO import StringIO as BytesIO
@@ -53,3 +54,4 @@ else:
     import tablib.packages.dbfpy as dbfpy
 
     unicode = unicode
+    xrange = xrange

tablib/formats/_xls.py

@@ -5,7 +5,7 @@
 
 import sys
 
-from tablib.compat import BytesIO, xlwt, xlrd, XLRDError
+from tablib.compat import BytesIO, xlwt, xlrd, XLRDError, xrange
 import tablib
 
 title = 'xls'