Broader file permissions required for AWS Lambda

[troyready]

This would be ideal to use with AWS Lambda, but it has a requirement that files are readable by all users (otherwise a cryptic error about unpacking the zip is generated).

Might be easiest to just set the extended attributes to all files to 644, or to preserve the current behavior by default then maybe an option would be better.

[troyready]

My diagnosis here was incorrect. The current lack of permissions data does not seem to be a problem (I'll create a PR for the real issue).

For posterity, I'll note that it would be simple to add permissions data in initFileCentralDirTempl; something like

directoryHeader.writeInt16LE(20, 4 ); //createdVersion
directoryHeader.writeInt16LE(3, 5 ); //created OS (Unix, for permissions)
directoryHeader.writeInt32BE(0x2481, 38); //External file attributes (permissions, a+r)

[Madh93]

Thank you every much @troyready 👏

After applying your patch I've resolved this AWS Lambda error:

Calling the invoke API action failed with this message: Lambda was not able to unzip the file

As you say, this library fits perfectly to use with AWS Lambda to avoid function redeployments.