This commits introduce the feature "urn:AGL:widget:file-properties".
This feature actually only allows to set execution flag to files
of the widget.
Example:
<feature name="urn:AGL:widget:file-properties">
<param name="flite" value="executable" />
<param name="jtalk" value="executable" />
</feature>
Bug-AGL: SPEC-384
Change-Id: If13ca3b1015576317fd52cb9540b77d0e2675f67
Signed-off-by: José Bollo <jose.bollo@iot.bzh>