Ignore all IntelliJ project files.
Extracted key down handler

To resolve TVPJSFRMWK-1683 / HTMLCRB-1483, extracted the key down
routine into the _onKeyDownHandler method. This required changing
references to "self" closure variable to "this" within the
extracted method.
Extracted select handler and supporting functions

To support TVPJSFRMWK-1683 the supporting methods had to be moved
outside of the closure. Select handler logic also moved to supporting
method for consistency.