fix(jqLite): use .children to fetch child elements but fallback to .childNodes for SVGs in IE

e35abc9d broke `jqLiteDealoc` on SVG elements in IE because `.children` is not supported on SVGs in IE (https://developer.mozilla.org/en-US/docs/Web/API/ParentNode.children#Browser_compatibility).

This change adds an SVG test and fixes it by doing `.children || .childNodes`. I also added `.children` in a few more places in addition to where e35abc9d originally did. Although if the `.childNodes` fallback is always required for IE, is it still worth using `.children`?