removed defunct decoder management dialog
edit mode is reset upon decoder selection
added notification messages for empty decoder sets
CSS clean up
resolved issues with determining replicas
Merge branch 'feature/webui_decoders' into scala_2.11

* feature/webui_decoders:
  resolved issues with determining replicas
  CSS clean up
  added notification messages for empty decoder sets
  edit mode is reset upon decoder selection
  removed defunct decoder management dialog