Description of problem:
Books created using the "create_book" command do not validate against w3c
All HTML should validate against XHTML 1.0 Strict.
This problem is caused when you override xsl templates and do not override the
1. create_book --name Test_Book
2. use the w3c validator service on "Test_Book/tmp/en-US/html/index.html"
6 errors ""there is no attribute "xmlns"."
added default name space to xsl files