Animated PNG (APNG) support for Imager. ``` use Imager; use Imager::File::APNG; my @frames = Imager->read_multi(file => "foo.png", type => "apng) or die Imager->errstr; Imager->write_multi({ file => "foo.png", type => "apng", apng_delay => 1/60, }, @frames) or die Imager->errstr; ```