The fast seeking option. It seeks to the next keyframe which reduces seeking delay over 10 times, but makes the seeking very inaccurate as a side effect (usually up to few seconds from requested position).
Previously top revealer was set to fixed size, which caused a noticable video tearing along the revealer edge during its animation. This commit removes fixed revealer size, which in turn casues the revealer to cover whole video screen (default behavior), thus eliminates the tearing. Since overlay now becomes the top widget, all player notify signals were reconnected to it.
This adds Kodi-like semi-transparent overlay with current media title, hour and estimated time when video will end. The overlay is visible only on fullscreen mode.
Follow other GNOME apps designs by having fullscreen button on the right side of window header bar. The control panel had too many buttons already and we still need to make some space for playlist. This way "fullscreen" button will be on top bar while windowed and "unfullscreen" button will appear on the bottom right only when player entered fullscreen mode.
Create volume button with popover instead of using GTK provided volume button.
Creating new button with only needed elements is more efficient then removing unneeded items from pre-made volume button. This should also increase performance a little when changing volume, because now we generate new icon only when a change is needed. In pre-made button icon is regenerated on each volume change.
Seeking during slider drag is very CPU and HDD intensive task. We are requesting the player to keep seeking in VERY short amounts of time. This can be performed more effectively by doing a single seek after slider drop. Since this is a different behaviour then usually in media players, I am making this optional (enabled by default).
