(1) Can add graph widget with space or "enter" in host/item field
Step to reproduce:

1. Add widget
2. Type space or "enter" in host and item pattern field
3. Save widget

Result: widget is saved
Expected result: error that host and/or item cannot be empty

(2) Can't select host, if host name ends the same as previous added host
Step to reproduce:

1. Create two hosts with name "one" and "two one"
2. Add widget
3. Press select button an choose host with name "two one"
4. Again press select button and try to add host with name "one"

Result: can't add host with name "one", because previous host also ends with word "one"