Convert util functions to async-creators

[raineorshine]

There are a few functions left in util that dispatch actions. They should be converted to action creators. For each one:

1. git mv src/util/something.js src/action-creators/something.js
2. export default
3. Instead of dispatching directly, return the action.

• e.g. replace dispatch({ type: X, value: Y }) with return ({ type: X, value: Y )}
• If it dispatches multiple actions, return a thunk, e.g.

  return (dispatch, getState) => { 
    dispatch({ type: X, value: Y )}; 
    dispatch({ type: A, value: B )};
  }

4. Update import statements and wrap the call sites with dispatch.

• deleteThought
• importText
• loadLocalState
• restoreCursorBeforeSearch
• sync
• syncRemote

[raineorshine]

Fixed in #670