Improve Brightcove title extraction

[TRox1972]

For at least some videos using Brightcove, especially those without separate extractors, the 'wrong' title is extracted, e.g.

[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'-v', u'http://www.rollingstone.com/music/videos/norwegian-dj-cashmere-cat-goes-spartan-on-with-me-premiere-20131219']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2016.05.21.2
[debug] Git HEAD: e913537
[debug] Python version 2.7.11 - Darwin-15.3.0-x86_64-i386-64bit
[debug] exe versions: avconv 11.4, avprobe 11.4, ffmpeg 3.0.2, ffprobe 3.0.2, rtmpdump 2.4
[debug] Proxy map: {}
[generic] norwegian-dj-cashmere-cat-goes-spartan-on-with-me-premiere-20131219: Requesting header
WARNING: Falling back on generic information extractor.
[generic] norwegian-dj-cashmere-cat-goes-spartan-on-with-me-premiere-20131219: Downloading webpage
[generic] norwegian-dj-cashmere-cat-goes-spartan-on-with-me-premiere-20131219: Extracting information
[download] Downloading playlist: Norwegian DJ Cashmere Cat Goes Spartan on 'With Me' - Premiere
[generic] playlist Norwegian DJ Cashmere Cat Goes Spartan on 'With Me' - Premiere: Collected 1 video ids (downloading 1 of them)
[download] Downloading video 1 of 1
[brightcove:new] 4404576300001: Downloading webpage
[brightcove:new] 4404576300001: Downloading JSON metadata
[brightcove:new] 4404576300001: Downloading m3u8 information
[brightcove:new] 4404576300001: Downloading m3u8 information
[debug] Invoking downloader on u'https://secure.brightcove.com/services/mobile/streaming/index/rendition.m3u8?assetId=4404592834001&secure=true&pubId=3891678521001&videoId=4404576300001'
[hlsnative] Downloading m3u8 manifest
[hlsnative] Total fragments: 24
[download] Destination: Music Video-4404576300001.mp4
[download]   8.3% of ~23.41MiB at  2.24MiB/s ETA 00:25

It seems that the Brightcove extractor interprets the video as a playlist with a single video; the playlist title is the actual video title. Improving the Brightcove extractor so that it can better differentiate between playlists and single videos would solve the issue.