Add limit, offset, and totalPh params

Used for templating output but maybe not enough use case to justify the change? Here's an example, which is admittedly kind of hairy:
```
			        <ul class="medium-4 columns large-offset-2">
[[TaggerGetTags? &groups=`1` &toPlaceholder=`toSetTotalPhOnly`]]
[[TaggerGetTags? &groups=`1` &rowTpl=`tag_nav_list_item` &target=`2` &limit=`[[+tags_total:divideandroundup=`3`]]`]]
			        </ul>
			        <ul class="medium-4 columns">
[[TaggerGetTags? &groups=`1` &rowTpl=`tag_nav_list_item` &target=`2` &limit=`[[+tags_total:divideandroundup=`3`]]` &offset=`[[+tags_total:divideandroundup=`3`]]`]]
			        </ul>
			        <ul class="medium-4 columns end">
[[TaggerGetTags? &groups=`1` &rowTpl=`tag_nav_list_item` &target=`2` &limit=`[[+tags_total:divideandroundup=`3`]]` &offset=`[[+tags_total:divideandroundup=`1.5`]]`]]
			        </ul>
```
Maybe it's better solved with &tpl_N ??
Slight mod for consistent int casting
Trying out &tpl_ implementation

This looks slightly nicer in the front end: 
```
[[TaggerGetTags? &groups=`1` &toPlaceholder=`toSetTotalPhOnly`]]
[[TaggerGetTags? 
    &groups=`1` 
    &rowTpl=`tag_nav_list_item` 
    &target=`2` 
    &tpl_[[+tags_total:divideandroundup=`3`]]=`tag_nav_list_item_nth` 
    &tpl_[[+tags_total]]=`tag_nav_list_item`
]]
```
But there's some compromises in the Snippet with lots of extra looping through arrays etc.
Add limit, offset, totalPh and tpl_N params

* origin/pr/21:
  Trying out &tpl_ implementation
  Slight mod for consistent int casting
  Add limit, offset, and totalPh params