Pewlib

Update Nu instruments csv-as-lines to newer format.

**Full Changelog**: https://github.com/djdt/pewlib/compare/v0.8.2...v0.8.3

Fix error when importing numpy archives > version 0.8.0 but < 0.8.1.

**Full Changelog**: https://github.com/djdt/pewlib/compare/v0.8.1...v0.8.2

What's Changed
* Multi image overlap by djdt in https://github.com/djdt/pewlib/pull/1

**Full Changelog**: https://github.com/djdt/pewlib/compare/v0.8.0...v0.8.1

Changes to npz file format.
Performance increases in filtering.
Other fixes.

weighted_linreg no longer uses weights when calculating the residual error

Fix thermo import of large row order files.