Refactor getFlatPackageInfo to better deal with bad xar compression.
Refactoring getFlatPackageInfo -  Only extract the Distribution file or PackageInfo file(s) instead of the entire package. Works around an issue with bad xar compression with certain flat packages.
Change order of file discovery to match original order.
Merge pull request #402 from bruienne/master

Refactor how getFlatPackageInfo runs xar