There's not much I can do for plugins with invalid headers (e.g. TES4 Oblivion plugins), so just log the error and skip over it. A plugin row will not be created in the DB for invalid plugins.
It was useful to crash the process on parse errors before when I was working out the kinks in the parser, but I think I'm confident enough in it now to skip over the parse failures and defer analyzing the failures until after the fact to make sure there still isn't a bug in the parser and I skipped over a valid TES5 plugin.
Also fixes the plugin span logging in the delate64 error case when extracting zip files.
Don't crash if metadata link 404s.
If extracting file from zip fails, try using linux unzip command instead. This fixes errors due to deflate64 compression.