Revert "Adds AndroidAnnotations library. Trying it out on MainActivity"

This reverts commit 0abd754692816ea9032687bd4f80a50093b7637d.
Revert "FeedbackActivity now uses AndroidAnnotations as well"

This reverts commit 2738712250c91f831503c1bfb8c7347cbd01e75e.
Add Butter Knife and try it out on Main and Feedback fragments