Fixed Issue #17

Added Blackjack max bet button - also took the liberty to add a min bet button.

HTML for the blackjack controls should now be:
```
<div class="row1">
    <button class="customBetButton button-max btn btn-inverse" style="font-size: 71%;">max</button>
    <button class="customBetButton button4 btn btn-inverse" style="font-size: 71%;">1/2</button>
    <button class="customBetButton button3 btn btn-inverse" style="font-size: 71%;">-1</button>
    <button class="customBetButton button2 btn btn-inverse" style="font-size: 71%;">+1</button>
    <button class="customBetButton button1 btn btn-inverse" style="font-size: 71%;">x2</button>
    <button class="customBetButton button-min btn btn-inverse" style="font-size: 71%;">min</button>
</div>
```