Version 0.11.0

• [SEMVER_MAJOR] Bump minimum rustc version to 1.9.0, required by dependencies
• [SEMVER_MINOR] Allow calling optimization presets via crate using Options::from_preset
• [SEMVER_MAJOR] Return proper PngError type which implements std::error::Error from Results
• Performance optimizations

v0.10.0

• [SEMVER_MINOR] Make clap and regex dependencies optional
  • Enabled by default, needed for executable build; can be disabled for use in crates
• Remove reduction from palette to grayscale, which was not working and provided minimal benefit

v0.9.0

• [SEMVER_MAJOR] Significant refactoring of modules
• Use itertools to cleanup areas of code
• Use multiple threads for filtering trials

v0.8.2

• Fix issue where images smaller than 4px width would crash on interlacing (#42)

v0.8.1

• Minor optimizations
• Fix issue where interlaced images with certain widths would fail to optimize

v0.8.0

• [SEMVER_MINOR] Add support for optimizing PNGs already loaded into memory via library function

v0.7.0

• Minor compression improvement on interlaced images
• Performance optimizations
• [SEMVER_MINOR] Move default Options into a Default impl
• [SEMVER_MINOR] Add option for setting number of threads (#39)

v0.6.0

• Fix issue where output directory would not be created if it did not exist
• Use miniz for compression strategies where it outperforms zlib
• [SEMVER_MINOR] Partially implement -p / --preserve, as far as stable Rust will allow for now
• [SEMVER_MINOR] Implement --fix to ignore CRC errors and recalculate correct CRC in output

v0.5.0

• [SEMVER_MINOR] Palette entries can now reduced, on by default (#11)
• Don't report that we are in pretend mode if verbosity is set to none
• Add cargo bench suite (#7)

v0.4.0

• Performance optimizations
• [SEMVER_MAJOR] -s automatically infers --strip safe (#31)
• Update byteorder and clap crates
• Fix issue where interlaced images incorrectly applied filters on the first line of a pass