Add display of current maximum bitrate in the 'CodecInfo' overlay window.

Fixed the max bit rate value reset at the end of play.
Enlarged the size of the Confluence skin codec information window to accomodate the new information.
Added a log at the end of play printing some information about codec dropped frames behavior.
Added indication of the version we are running in System > System info.
Added heat info and cpu usage info to the information screen in video player.

Display the info in Video OSD or in info window.
Updated the height of the upper fade area in show info.
Modified the fan speed display, to better manage the missing fan on the board (some HTPC don't have it, or don't have the speed measurement).
Added system fan speed to the CPU temperature label in system info window.
Added cpu speed info to the information screen in video player.
Fix after b85b12f8cc0855e7d4d448886a4d60adeba7ce6e (kill CStdString)
[confluence skin] Changed behavior of DialogKaiToast info window: now scrolls the message text and wait only 500 ms before restarting scrolling
[xbmc] Changing the way the info window display time work: now it's depending on the message length (more characters leads to more seconds, 200 ms each character allocated), with a minimum of 2 seconds