manpage: various improvements

Took a superficial look at the manpage, and fixed whatever I spotted.
Makefile: restore manpage dependency rules

Broken by commit 0054073.

Also add them to the pdf target.
mplayer: mentioned --list-options in --help output

It's annoying for users if you can't get a list of options with --help,
but on the other hand, printing all options would be overkill. So just
mentioned --list-options.
stream: force demuxer of cached stream, fixes cdda:// + cache
command: make title property unavailable if there's no support

Instead of returning 0 if the stream doesn't have title info, make the
property unavailable.
stream_bluray: return number of titles

So that the "titles" property returns the number of titles.
quvi: coerce libquvi 0.4 support into allowing format switching

libquvi 0.4 doesn't allow us listing the formats supported by a
streaming site without doing additional network accesses, so switching
formats was not supported with it. (It's different with libquvi 0.9.)

But the most important case is switching between SD and HD. Usually,
--quvi-format=default will get SD, while --quvi-format=best gives HD.
Use this, and pretend that an URL supported by libquvi 0.4 supports both
of these. "cycle quvi-format" will switch between these. If the user
specifies something else via --quvi-format, this is included in the list
of switchable formats additionally to "default" and "best".
quvi: restore playback position when switching formats

This simply issues a seek after reloading.
mplayer: print libquvi results in verbose mode

Helpful for debugging.