HTTPS support

[nmr50]

Hi ! I did notice several times that youtube-dl won't operate on secure server urls (HTTPS).
Here is the log:
C:>youtube-dl -v https://russia.tv/video/show/brand_id/5206/episode_id/1291971/viewtype/picture/
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'-v', u'https://russia.tv/video/show/brand_id/5206/episode_id/1291971/viewtype/picture/']
[debug] Encodings: locale cp1251, fs mbcs, out cp866, pref cp1251
[debug] youtube-dl version 2016.04.06
[debug] Python version 2.7.10 - Windows-7-6.1.7601-SP1
[debug] exe versions: ffmpeg N-79107-g30d1213, rtmpdump 2.4
[debug] Proxy map: {}
[generic] picture: Requesting header
WARNING: Could not send HEAD request to https://russia.tv/video/show/brand_id/5206/episode_id/1291971/viewtype/picture/: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)>
[generic] picture: Downloading webpage
ERROR: Unable to download webpage: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)> (caused by URLError(SSLError(1, u'[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)'),))
File "youtube_dl\extractor\common.pyo", line 371, in _request_webpage
File "youtube_dl\YoutubeDL.pyo", line 1935, in urlopen
File "urllib2.pyo", line 431, in open
File "urllib2.pyo", line 449, in _open
File "urllib2.pyo", line 409, in _call_chain
File "youtube_dl\utils.pyo", line 859, in https_open
File "urllib2.pyo", line 1197, in do_open

[yan12125]

This website has misconfigured SSL certificates:

$ echo | openssl s_client -connect russia.tv:443 -servername russia.tv
CONNECTED(00000004)
depth=0 C = RU, ST = Moscow, L = Moscow, O = VGTRK, CN = *.russia.tv
verify error:num=20:unable to get local issuer certificate
verify return:1
depth=0 C = RU, ST = Moscow, L = Moscow, O = VGTRK, CN = *.russia.tv
verify error:num=21:unable to verify the first certificate
verify return:1
---
Certificate chain
 0 s:/C=RU/ST=Moscow/L=Moscow/O=VGTRK/CN=*.russia.tv
   i:/C=US/O=thawte, Inc./CN=thawte SSL CA - G2
 1 s:/C=US/O=Thawte, Inc./CN=Thawte SSL CA
   i:/C=US/O=thawte, Inc./OU=Certification Services Division/OU=(c) 2006 thawte, Inc. - For authorized use only/CN=thawte Primary Root CA
(...remaining omitted...)

The subject of the second certificate is not the issuer of the first certificate. As a result, a valid certificate chain can't be formed.

For users, --no-check-certificate can avoid the problem.