Mouseover delay

[amclin]

This allows for setting a timeout not just for the mouseout delay, but also a mouseover delay.

• Leave timeout unset, no change in behavior, (same as timeout=0)
• Set timeout to single number, no change in behavior, timeout only applies to mouseout delay
  • { timeout: 500 }
• Set timeout to an array, the first value will be used for mouseenter delay, the second value will be used for mouseout delay
  • { timeout: [250,500] }

[usmonster]

Closing pending further discussion on #6. (See also #61.)