• Refactored low-level methods for reading and writing zip files
  in zip64 format. Added new parameters and return values to
  most of these. Extended constants in Archive::Zip to cover
  zip64 formats and lengths.
  
• Added public APIs
  Archive::Zip::Archive::zip64
  Archive::Zip::Archive::desiredZip64Mode
  Archive::Zip::Archive::versionMadeBy
  Archive::Zip::Archive::versionNeededToExtract
  Archive::Zip::Member::zip64
  Archive::Zip::Member::desiredZip64Mode
  and constants
  Archive::Zip::ZIP64_AS_NEEDED
  Archive::Zip::ZIP64_EOCD
  Archive::Zip::ZIP64_HEADERS
  plus POD on these.
  
• Added tests for zip64 format in t/21_zip64.t and more test zip
  files below t/data. Extended tests in t/02_main.t to perform
  all existing tests in all possible desired zip64 modes.
  
• Extended methods
  Archive::Zip::Member::localExtraField
  Archive::Zip::Member::cdExtraField
  to perform format checks when called as setters and to reject
  any zip64 extended information extra fields passed by the user.
  Extended POD and tests in t/02_main.t accordingly.
  
• Setting {'compressedSize'} after writing central directory
  header.
  
• Added new optional parameter $noFormatError to method
  Archive::Zip::_readSignature to silence any format errros when
  testing for signatures.
  
• Added error handling for potentially failed object conversion
  after calling method Archive::Zip::Member::_become. Factored
  in method Archive::Zip::Member::_becomeDirectoryIfNecessary
  into caller.
  
• Changed methods
  Archive::Zip::Archive::contents
  Archive::Zip::Member::contents
  (and all inheriting from these) to consistently return a pair
  ($contents, $status) when called in list context and a scalar
  $contents when called in scalar context. Extended tests in
  t/02_main.t accordingly.
  
• Changed method Archive::Zip::Member::extractToFileHandle to
  accept a file name instead of a file handle when extracting
  symbolic links. Changed lower-level and higher-level methods
  to use that feature. Cleaned up code related to the handling
  of symbolic links. Added creation of intermediate directories
  in method Archive::Zip::Member::extractToFileNamed for symbolic
  links as well. Reporting errors from symlink call as AZ-error.
  Added POD and test zip file t/data/symlink.zip and tests in
  t/26_symlinks.t for these changes.
  
• Cleaned up code and added comment related to that highly
  dubious (?) {'wasWritten'} logic.