Added taglist directive.

Added an angular directive which emulates the bootstrap tag input plugin.
General Rewrite

  - Wrote api service to interface with the discoverable API
    'methods' generated by the admin api koastModule
  - Rewrote backup service to be consistent with new api interface
  - Stubbed out user-service to replace the existing one which assumes
    a koast-angular compatible API
  - Added collection tagList to backup panel