FIX: Dropdown component menu markup. New options.

Fixed broken markup of dropdown component.

Also added options:

    * `emphasis`: for dropdown button styling (info, danger, etc.)
    * `icon`    : to set dropdown icon. Defaults to caret-down
FIX: Single story view modals inside jumbotron

They were awkwardly large because of this.
Answers full management

Answers can now be drafted, applied and removed. This commit contains controller as well as view logic.
FIX: Crashes displaying question w/o answer drafts

Quite obvious, but easier to dig by looking at diff then to explain in plain words :)
FIX: Redirect to question after answer removal
FIX: Home view crash on answer to removed question

News-feed component expected to have question populated in draft (saved or applied). But when question was removed afterwards, it couldn't get populated and was set to null. This was causing type error upon accessing attributes of null.

The fix is to skip displaying such entries.
Display remove answer entry correctly in home view
Question not found error in single answer route