Game Compressor 1.0.3

Game Compressor 1.0.3 is a small stability release for compressed .ffpfsc
images and the compression dialog.

Compared against v1.0.2.

Fixes

• Improved USB-to-USB compression reliability by zeroing PFSC/PFS padding that
  could otherwise prevent the final .ffpfsc from mounting.
• Fixed compressed APR-EMU update and AMPR index rebuild finalization so their
  rewritten .ffpfsc images also have clean outer padding.
• Let validate and repair clean older Game Compressor .ffpfsc wrapper padding
  before mount, while skipping that cleanup for third-party layouts and still
  continuing validation.
• Clarified that Compress always outputs .ffpfsc; the format choice is for
  the nested image inside the compressed archive.

See CHANGELOG.md for the concise change list.