Optimize multiple apply calls

Template bodies that have more than one apply call can be optimized in a following way:

``` javascript
apply(...);
apply(...);
apply(...);
```

could be transformed

``` javascript
var _applies = _getApplies(this);

_applies[0](...);
_applies[1](...);
_applies[2](...);
```

`_getApplies` will do template matching to go as deep as possible in xjst's decision tree
