#25602 Adds a new method bundle.execute_hook_expression()

Adds a new method that lets you execute a hook expression directly. Also updates execute_hook_by_name to support arbitrary hook formats and not just files in the configuration formats. This method is now legacy and the new execute_hook_expression method is the recommended way to execute arbitrary hooks.

![screen shot 2014-06-09 at 17 51 03](https://cloud.githubusercontent.com/assets/337710/3219562/edf2cd30-eff6-11e3-93a5-7fb099930ec0.png)