Updates icons in discussion show page

Created two new buttons based on the current ones available.
Removed unused code.
Removes comments module, there was already a comment directive on the components folder. We don't know yet if a module is required.

![screen shot 2014-12-29 at 16 01 39](https://cloud.githubusercontent.com/assets/934580/5570098/0af8046e-8f74-11e4-82c1-5925527af395.png)

Yes, it's necessary, we should always follow the rules even if it looks ugly sometimes, it's consistent with the rest of the code and allows for clarity of reading.

The thing that's probably a problem here that I've already pointed out is that we are making modifiers for buttons with icons when we could make new components, but if it gets out of hand we can refactor easily I believe.