Add some cases to test the link and base elements

Signed-off-by: xiaojunwu <xiaojunx.a.wu@intel.com>
Update tests for the base element a litte, and remove the link tests

- onerror checkpoint in link_events.html is covered by link-style-error-01.html
- link_type_mismatch_source.html uses setTimeout(); moreover, it won't fail
  even the feature is not implemented.
Update according to the new template

1. Update the code format
2. Update the reference specification
Update base_multiple_manual.html to automatical testing
Update the href attribute of base element
Merge pull request #453 from xiaojunwu/xiaojunwu/the-link-base-element

Add tests for the base element; r=zcorpan+Ms2ger