Fix the HTML formatters handling of output from hooks

In v1.3.x the HTML formatter delays the output from the Before hook until after the first step, and delays the output from the After hooks to until after the first step in the next Scenario:
![html_output_v1_3_x](https://cloud.githubusercontent.com/assets/2105308/4324703/5450b78a-3f5d-11e4-9c68-9dcbdf1dc99e.png)

In v2.0.0.beta.1 the output from AfterStep and After hooks was not printed at all. With the changes in #732 and #738, the handling of hook output was brought up to the same behaviour as v1.3.x. This PR fixes the remaining issues with respect to the HTML formatters handling of hook output, resulting in this behaviour:
![html_out_v2_0](https://cloud.githubusercontent.com/assets/2105308/4324789/fbbe94e2-3f5d-11e4-9d1f-b29af36c975d.png)

Fixes #731.