Allow getting updated man page via -U

[Vrihub]

It would be nice if users who update their local copy via "youtube-dl -U" could also get an updated copy of the man page.

I guess this should imply adding a copy of the man page source file to the zipped youtube-dl executable, and adding a command-line option to generate/display the man page (something like "youtube-dl --man", following the example of "youtube-dl --help").

[yan12125]

Python's pip tool provides such a functionality. That is, man pages are installed and upgraded with the package. Check installation instructions and upgrade instructions for how to use pip with youtube-dl.