Deferred same origin check to CSP (closes #209)

* Added forced same origin check on start_url
* Deferred same origin check to CSP
* Letting HTML handle the fetching form the link element
Described how manifest+CSP works (closes #207)
Added info about i18n discussion (closes #212)
i18n wording change

Made change as suggested by @kenchris to i18n text
Merge pull request #221 from w3c/intl

Added info about i18n discussion (closes #212)
Merge pull request #219 from w3c/same_origin

Deferred same origin check to CSP (closes #209)
Fixed typo
Fixed 'an HTML' typo
Merge pull request #220 from w3c/CSP

Described how manifest+CSP works (closes #207)
Removed tabs

Removed tabs that were confusing HTML5 Tidy.
fixed markup error
tidy