Only strip newline in OrderedStreamingForkController

Only strip newline in OrderedStreamingForkController

The controller should pass through lines of input exactly as
they were provided, only stripping the trailing newline that
delimits items. The trim was making `door` and `door ` equivilant
but for the use case in search the distinction is important.

Additionally check that the line is actually empty, don't throw
away inputs like '0' which are falsy.

Change-Id: Ifac910543fdb46a27da021e831e3e18befefcfc5