apply bootstrap css on ticket list with display of images

![ticket_list_v1](https://cloud.githubusercontent.com/assets/4461484/2680917/d0c5db64-c187-11e3-9643-4f45f562cf25.png)

@YanshuoH Please check this out. Tell me what u think about it. Shall we change this list a little bit "low-weighted"? (without too much info)
I'll figure out the filters on the left side of the page.
GL!