Make ROI Length calculation method public
Update dependency versions

- IJ2 to 2.0.0-beta-7.9
- IJ1 to 1.48s
- SCIFO to 0.10.2
- SciJava to 2.13.0
Version 0.4.4 release

0.4.4 Release Notes
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Note: This version of Slide Set is a beta release.

Updates from the previous version:

- Update to ImageJ version 2.0.0-beta-7.9