[sockshare] Add new extractor
[dropbox] Fix test and add support for spaces in filenames
[cnet] Fix title extraction

URLs are still missing
[vimeo] Update test description
[funnyordie] Fix test description
[chilloutzone] Fix test description
[wdr] Replace test case
[tagesschau] Remove test case

See http://de.wikipedia.org/wiki/Depublizieren for the sad rationale.
Merge remote-tracking branch 'naglis/sockshare'

Conflicts:
	youtube_dl/extractor/__init__.py
[sockshare] Simplify (#3268)