Feature #5157 : complete media slider

- fixing permalink problem ...
- fixing a navigation problem around user notification (the popup was not displayed anymore)
- taking into account Nicolas's returns (except the one about the thumbnail hovering from the content album view because of a functional choice to perform before doing something)
- implementing a new embedded player mechanism in order to have a huge separation between media player integrations in several parts of Silverpeas and the code of the media player itself (to display a video or to listen a sound, use <view:includePlugin name="embedPlayer"/> that provides jQuery Silverpeas Embed Player HTML generation...)

I have tested a lot of HTML5 media player each one featured with Flash fallback (JPlayer, VideoJs, Projekktor, MediaElement, Flowplayer...). But whatever the HTML5 player, it was always existing something wrong. I think that it is because of the HTML frameset use...
So I turned one's coat and I have implemented this rule : if flash player exists on client machine, then it is used with wonderfull FlowPlayer Flash API, otherwise HTML5 native player is used.

I think, the next (very) useful step could be the integration of the use of RTMP protocole in order to obtain pseudo streaming of our video content. By this way, the huge videos could be read without waiting for their complete download.

Ho, and yes, I'm on holidays, but I wanted to finish this part to avoid to lose to much time at my return, and to permit to integrators to verify my work whereas I'm still in the swimming pool on a inflatable mattress being to drink a Pastis :-)

Please don't forget to check PR : https://github.com/Silverpeas/Silverpeas-Core/pull/544