Integrated LibreOfficeLight into gbuild.
added lo.xcconfig and Resources (needed to link with LO and run LO)
added swift --> C interface for LOkit
add known commands from JS client

added C++ condition in LibreOfficekitInit.h (inline no good in a C file)

Change-Id: I19ebe8912546408bf701c96c0c63541d6e37cad8
Reviewed-on: https://gerrit.libreoffice.org/35430Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: jan iversen <jani@libreoffice.org>