internal dvd player. make channelup/channeldown keys behave like the jumpfwnd/jumprwnd keys.

[skamithi]

problem with internal dvd player reported on mythtv-dev alias where user say "jump back/jump forward" messages followed by a hang, instead of mythtv jumping to the next title.

if you hit the channelup/channeldown button in a title where there is only one chapter, the dvd will not skip to the next title. instead it may hang.

will create a function , or two, that both the channelup/channeldown & jumpfwnd and jumprwnd can call when playing a dvd.

this function will perform the tasks done shown in the jumpfwd and jumprwnd dvd sections of tv_play.cpp.

channelup ->jumprwnd : skip to the previous chapter if available, or skip to the previous title, if possible

channeldown -> jumpfwnd: skip to the next title if at the end of the title, or jump to the next chapter if available

[skamithi]

(In [11014]) Closes #2275. internal dvd player. make channelup/channeldown keys behave like the jumpfwnd/jumprwnd keys.