1.0.0: Unique given sources, BZ2

The first major release includes final touches to the packaged ZIP file.

• Merged PR #5: Unique given sources, preventing them being added to the
  ZIP file twice
  (@thekid)
• Also support bzip2 compression if PHP extension is loaded, but keep
  preference on gzip, which has performed better in my tests.
  (@thekid)