Add end word boundary for if/else/case constructs. Fixes #4

Wraps the if/else/case language constructs in an ending word boundary as well to prevent it from matching other words like `caserver`.

Before word boundary update:
![old](https://f.cloud.github.com/assets/283234/2453231/9171810c-aedb-11e3-8628-b1f0403ff476.png)

After word boundary update:
![new](https://f.cloud.github.com/assets/283234/2453233/931340ea-aedb-11e3-882a-76ef585c14c9.png)