v0.8: Option to enforce cropping to iMCU boundaries; adjustable zoom

What's Changed

• Implement a command-line option to force JPEG bottom and right edges to be on iMCU boundaries. by @Ndolam in #116
• Implement a "poor man's" zoom feature. (The image gets bigger and sm… by @Ndolam in #118
• cropgtk: properly parse the commandline with argparse by @jepler in #120

New Contributors

• @Ndolam made their first contribution in #116

Full Changelog: v0.7...v0.8