Bug 926302 - 1/3: B2G DSDS - numRadioInterfaces and default service ids.  Interface changes. r=hsinyi
Bug 926302 - 2.a/3: refactor preference/settings names. r=gene
Bug 926302 - 2.b/3: implementation. r=gene,hsinyi,khuey
Bug 926302 - 3/3: test cases. r=hsinyi