File and folder names cannot end with dots on Windows. So replace the
trailing dots with underscore consistently with how some other zip tools
(such as 7-zip) handle this case.
The original implementation was based on ZipArchive::getStream() which
turns out to be very slow and if the archive contains many files, the
unzipping performance is very slow.
The patch changes the implementation to use ZipArchive::extractTo()
unless the extracted entry path contains a folder name ending with dot
(such as some/path./to/file.txt). There is a known upstream bug in the
PHP ZIP extension #77214 (also #74619 and #69477) so that we fall back
to keep using the stream in those cases.
The progress variable wasn't always passed to recursive calls. This
caused a lack of progress() calls between files in subfolders. I
added a unit test for this situation.
Changes:
* zip_packer can create empty zip archives
* new option to ignore problematic files when creating archive
* detection of non-existent files
* debugging messages for opening of faulty zip archives
* coding style improvements
* no PHP 5.2 hacks
* more unit tests
