Add tests for the browsing contexts
Update codes as review suggestions

1. Change the document charset
2. Change the to xhtml
3. Remove help link
4. BackCompat test and etc

Signed-off-by: xiaojunwu <xiaojunx.a.wu@intel.com>
Remove the doctype of xhtml
Do the testing right after the iframe element is appended
Remove doctype and update feedline characters
Merge pull request #634 from xiaojunwu/submission/xiaojunwu/browsing-context-first-created

Add tests for the browsing contexts