Fix API documentation comments

Removed blank lines between Parameters/Returns heading and their tables
Changed API documentation header and footer
Added None below Parameters & Returns where applicable
Open-webOS-DCO-1.0-Signed-off-by: Kalindi Pathare <kalindi.pathare@lge.com>

Change-Id: I48de9b0f31ddc67648d24fe6e7775dfdb7d52120