localize "remove" and some page titles
show localized err msg on series_bookmarks
create Alert component, use for Chapter error
localize "loading chap info" message
add error handler for Search & Series
better wording for error messages
make Alert optionally disimissble
add Series route's error message

Also:

- Don't call echo() inside Alert component. Its parent component should
  do that.

- Yet another wording change for `unknown_server_error`