Application handler can do anything with a stream object (including close it).
Once the stream is closed, Unit creates a new stream.
This closes#616 issue on GitHub.
Some Perl compile options affects ABI and not using them while compiling
our module resulted in non-working build.
Notably on 32-bit Debian 10, Perl is built with -D_FILE_OFFSET_BITS=64
and our module after being compiled without this option caused segmentation
faults in unexpected places.
