Fixed bugs related to #each blocks

When model.at() was used to get the path for an element in an #each block it would give an incorrect index if there was text or spaces between the #each block and the contained element.

The fix skips any text nodes in the #each block.

There was another bug where updates to #each blocks wouldn't remove all the right elements when there was space inside the #each block but outside the one element it can contain.

Both bugs could occur for code like:
```html
{#each}
<li>{.}</li>
{/}
```