feat(animation): add option to disable animation on all setVisibility fn

[ghiscoding]

• this PR allows to disable the built-in slide animation (which uses jQueryUI), I have a particular use case where I toggle the filter bar after the grid creation and I don't want to see the animation at all, it has to happen instantly without the user noticing the filter header row was ever open.

• added a boolean flag as 2nd argument to each functions, the default is still the animation, so it won't change default behavior

• manually tested with the Grid Menu Example with/without animation, see animated gif below

  • note the gif start with animation, then later reload the page and disable all animation with extra false argument

[ghiscoding]

@6pac
Hello Ben, do you think you'll have a chance to review my 2 PRs in the coming couple weeks? Not a huge rush but I'd be happy to see them merge eventually :)

This one in particular touches slick.grid core, so you might want to review it. The other PR is for a plugin, which I guess I could have merged myself.

Cheers mate.