added some missed test files from libpng; fixed authors for poppler

source/libs/libpng/libpng-src/contrib/oss-fuzz/README.txt

source/libs/libpng/libpng-src/contrib/oss-fuzz/build.sh

.../libpng/libpng-src/contrib/oss-fuzz/libpng_read_fuzzer.cc

...ng/libpng-src/contrib/oss-fuzz/libpng_read_fuzzer.options

source/libs/libpng/libpng-src/contrib/oss-fuzz/png.dict

.../libpng/libpng-src/contrib/testpngs/crashers/bad_iCCP.png

.../libpng/libpng-src/contrib/testpngs/crashers/badadler.png

...bs/libpng/libpng-src/contrib/testpngs/crashers/badcrc.png

...-src/contrib/testpngs/crashers/empty_ancillary_chunks.png

...libpng/libpng-src/contrib/testpngs/crashers/huge_IDAT.png

.../libpng-src/contrib/testpngs/crashers/huge_bKGD_chunk.png

.../libpng-src/contrib/testpngs/crashers/huge_cHRM_chunk.png

.../libpng-src/contrib/testpngs/crashers/huge_eXIf_chunk.png

.../libpng-src/contrib/testpngs/crashers/huge_gAMA_chunk.png

.../libpng-src/contrib/testpngs/crashers/huge_hIST_chunk.png

.../libpng-src/contrib/testpngs/crashers/huge_iCCP_chunk.png

.../libpng-src/contrib/testpngs/crashers/huge_iTXt_chunk.png

...rc/contrib/testpngs/crashers/huge_juNK_unsafe_to_copy.png

...-src/contrib/testpngs/crashers/huge_juNk_safe_to_copy.png

.../libpng-src/contrib/testpngs/crashers/huge_pCAL_chunk.png