New Features - Prefixing, Suffixing, Number Commas and Ordinal

I've created a few new features, if you would prefer me to rip these out and submit them as individual PR's, let me know.

# Prefixes and Suffixes
Pretty simple, by using `data-prefix` and `data-suffix` you can prepend and append whatever you like to your numbers. Both the prefix and suffix will appear from the start and won't change throughout the countTo process.
```
<span class="timer" data-from="0" data-to="100" 
      data-prefix="Example: " data-suffix=" points"></span>

<script type="text/javascript"><!--
    $('.timer').countTo();
//--></script>
```
**Example: 100 points**

# Number Commas
By setting `data-commas` to anything (e.g. `data-with-commas="true"`), the current value during the countTo process will have commas placed in the correct locations. 

For example if you have `data-from="0"` and `data-to="1500"`, no commas will appear until the value has reached 1,000, at which point it (and all subsequent values) will be formatted with a comma.
```
<span class="timer" data-from="0" data-to="1500"
      data-with-commas="true"></span>

<script type="text/javascript"><!--
    $('.timer').countTo();
//--></script>
```
**1,500**

# Ordinal
By setting `data-ordinal` to anything (e.g. `data-ordinal="true"`), the value will be appended with the correct ordinal of the final `settings.to` value.

For example, if you have `data-from="10"` and `data-to="31"`, whilst the value is incrementing it will be appended with `st` as this is the correct ordinal for 21. I have tried setting this to dynamically update the ordinal as it increments/decrements, but doing it that way would lead to a weird bug where the ordinal would not change, and instead the ordinal would default to the ordinal of the `data-from` value.
```
<span class="timer" data-from="0" data-to="83"
      data-ordinal="true"></span>

<script type="text/javascript"><!--
    $('.timer').countTo();
//--></script>
```
**83rd**

# Correct Combinations
You can combine the usage of all 4 of these new tags and they'll play nicely together and with your current tags. `data-prefix` will always appear before the number, `data-append` will always appear after both the number and the ordinal.

```
<span class="timer" data-from="0" data-to="100" 
      data-prefix="Final Position: " data-suffix=" place" data-ordinals="true"></span>

<script type="text/javascript"><!--
    $('.timer').countTo();
//--></script>
```
**Final Position: 3rd place**
This seems like something that should be outside the scope of this function.  In other words, I'd only expect `ordinalHandler` to be called if `settings.ordinal` is truthy.