This commit should fix existing problems with Disqus and Google
Analytics enabled in the meta-yaml section of a note.
Before this commit they were blocked by the strict CSP. It's still
possible to disable the added directives using `addDisqus` and
`addGoogleAnalytics` in the `csp` config section.
They are enabled by default to prevent breaking changes.
Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>
