fix($animator): skip animation for initial show/hide

[olostan]

ngShow/ngHide directivies started animation just after rendering causing
unexpected behaviour of showing animation of elements that should be already
shown. This fix allows specifing "instant" parameter for $animator.show and
$animator.hide functions to skip actual animation.

More information is at #2309

[alexeygolev]

+1

[mhevery]

Thanks for the commit. We have already fixed this issue in a cleaner way.

[lukasmlady]

Hi, is the fix commited yet? The issue is still showing up after merging with the latest version of $animator.

[mhevery]

This is already checked into the master branch.

1. animation can only run if there are no other animations running above it. This prevents animation in animation bug
2. On initial render we create a fake parent animation and than render into it. This prevents animation on initial render