support for alternate links
Merge commit 'tags/v3.4' into alternate_nofollow

Conflicts:
	spec/sitemap_generator/alternate_sitemap_spec.rb
support for 'alternate nofollow'
README updated
old docs removal
Add version 4 release notes.
Add some notes
Default create_index to :auto and add a setter method
In group() don't modify the options hash passed in; handle case where use has only one group in a different file, force index to be created (edge case)

TODO: Fix specs
Work on fixing specs for create_index changes
Deprecate old methods.  Add a new 'namer' method for setting the namer that is distinct from the old accessor methods, otherwise it gets very difficult to support old code.

Fix some specs.
Fix sitemap_generator_spec specs
Fix forcing the index to be created when in a group
Fix groups specs
Update docs
Don't write out empty site maps
Fix defaults for new index name
Handle manually added links correctly

TODO:
Test output line description
Document removal of sitemaps_namer and sitemap_index_namer
Fix 2 failing specs
Do coverage analysis
All specs passing!
Remove rcov (use simplecov instead, but commented out)
Improve test coverage
Ellipsis: only add ellipsis if string is greater than maximum!
Update readme and code examples.
Update readme examples
adding documentation for adding sitemap to webmaster tools