PlayerPane: Change Pop-Out to Pop-In

[timfitzzz]

Rather than having the playerpane pop out into a separate window, the controls and clipslist should pop out, leaving the player itself within the initial browser window. This would be friendlier to streamers who are using application capture. The current implementation causes the player to move into a new window, requiring streamers capturing the browser window directly to capture the new window as well.

[timfitzzz]

On second thought, rather than removing the existing functionality, let's implement these sections as panes and make them generally removable.