Interpolated console while the game's paused

When the con_interpolate and con_speed CVars were added, it was only possible to interpolate the console while the game wasn't paused. It was noticeable to see the console not lower smoothly in offline games because at that point the game was paused. This is now improved by continuing to interpolate the renderer while the console's rising or falling during a pause, even when this normally wouldn't happen. I also took the liberty of doing some cleanup around P_Ticker.