Suggestion list to the recipient field

Add suggestion list to the recipient field.
When user starts typing in the recipient field, all matching results are shown in the list.

For ex. if user typed AD - matching results should include such names like AD MIN, AD MINISTRATOR, COMR AD E etc.

Matching letters should be displayed with bold font.

Acceptance Criteria:

1. names should be dislplayed regardless of case;
2. 10 matched names should be displayed in the suggestion list
3. UI: drom-down should be in the same size as recipient field (support last versions of Mozilla, IE, Chrome, Opera)
4. pay attention, that username can be in different languages and contains special symbols
5. recipient without PRIVATE_MESSAGES should not be in the list
6. start search from third symbol (performance)