LB-723: Add provider error after incorrect url has been provided

Test provider url before saving.
Fix localization.
LB-754: Create zeit theme

changed made by Nikola added.
STT theme fix

> soundcloud icon added
> compact1 and mobile classes margin bug fix
> comment icon added for comment posts
> soundcloud iframe double height bug resolved
Merge pull request #210 from nistormihai/zeit

LB-754: Create zeit theme
LB-589: Doplicated posts in embed after reordering.

Fix view lookup.
Default embed theme CSS refactor

> soundlocudpost sourceicon added
> soundcloud iframe bug fixed
> liveblog header bar changed
> IE default border on image links removed
> change text line height for better readability
Tageswoche theme CSS refactor

> header changed
> soundcloud icon added
> youtube and soundcloud responsive embed objects
> youtube remove default blue link color on title
LB-737 : Embed URL-> STT theme -> Permalink hyperlink is NOT presented adequately on all browsers and devices

Fixed
Merge remote-tracking branch 'sourcefabric/liveblog-15' into embed-themes-fixies
Merge pull request #211 from petrjasek/lb-589-reordering-duplicates

LB-589: Doplicated posts in embed after reordering.
Merge pull request #204 from petrjasek/lb-723-test-provider-url

Lb 723 test provider url
Merge pull request #212 from nidzix/embed-themes-fixies

Embed themes fixies