CMS-3362 Double clicking ComboBoxOptionFilterInput shall not remove caret from input

Fixed caret disappear on double click on Input Filter.
CMS-3362 Double clicking ComboBoxOptionFilterInput shall not remove caret from input

Fixed row selection on spacebar press for combo boxes with max
occurrences of one.
Added support for spacebar press disabling, when selections maximum is
reached.
Merge pull request #696 from enonic/CMS-3362

CMS-3362 Double clicking ComboBoxOptionFilterInput shall not remove caret from input