Added comments support.

* Added component
* Added markdown parser adapter for parsing
* Added bundle
* Tested both
Fixed comment bundle dependencies
Merge pull request #272 from elcodi/feature/comments-component-and-bundle

Added comments support.
Issue #273 #274

* Implemented Votes and service to manage them
* Refactored cache methods. Placed in its own class
* Added eventDispatcher with comment and votes events
* Added eventListener for empty cache
* Tested component and bundle
Merge pull request #277 from elcodi/feature/comments-component-and-bundle

Issue #273 #274
Added proxy-manager dependency