mod_twitter: fix import of tweets with special-html chars, was double escaped in title.

(cherry picked from commit 228767b2309c382daf24962f3bafdb6268e6241d)
mod_admin: always show media content, independent if size was defined.

(cherry picked from commit ecb83bba5377a62a1419cd59f0c98178689db1f7)
mod_oembed: sanitize received oembed code html and texts.

(cherry picked from commit d83416a1570d4f46d932a43062741d1eaf1c5e86)
core: add instagram js and urls to whitelist.

(cherry picked from commit 3427c0353bd530afea2f9f2147da4b17db633852)
mod_survey: fix problem where displaying the results did not work due to move sanitization functions.

(cherry picked from commit 3ff889456747c9d9a5d9e3932dd856063211f7ab)