Onscreenapp is a qt application for showing onscreens.
Applications can show/hide onscreen by calling homescreen-service's
showWindow/hideWindow verb. Applications also can customize onscreen's
title,type, display contents and buttons. Some images about onscreen
pattern had uploaded in JIRA SPEC-1967.
Bug-AGL: SPEC-1967
Change-Id: Ica1b5912e109d39eb6743144cfc523dbf64cac9f
Signed-off-by: wang_zhiqiang <wang_zhiqiang@dl.cn.nexty-ele.com>