Some more frontend stuff/Native Diaspora reshare

**Some more frontend stuff:**
- in the delegation setup, the settings menu appears in the left (instead of a blank space)
- same is done with the menu for "Export personal data". There was an outdated menu.
- When a mobile theme was activated, the preview always showed a wrong preview
- In the OAuth settings there was a problem when "cancel" was hit - since the link is needless, it was removed
- In "vier" there was a gray line below the username when it was selected in the navigation
- the link for "preview" is now a button.
- Dreamwidth and InsaneJournal are now adopted to the new layout as well.
- Disabled networks are grey.

**Backend stuff:**
- When a message is repeated and it is from Diaspora, then the message will be repeated as native reshare, if it was a pure repeat without additions.