Help: Remove unused signal

Change-Id: I64f5faaccec513848cc2eab83f98927475e67d54
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
Text browser help viewer: Remove unnecessary state.

Change-Id: Ie8ecc98a065a5f9d79be45a6921f7b2165c75ead
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
Help: Remove some unnecessary direct accesses to central widget

Change-Id: I04046b792f5b5264534e2654db28fcb18638869b
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>