Rapidtide

* (happy, happy_legacy, simdata) This release corrects a flaw (or perhaps more accurately an ambiguity) in slice time specification. In FSL slicetime files, slicetimes are specified in fractions of a TR. In .json sidecars, they are specified in seconds. This is now detected on file read, and slicetime files are now converted to seconds. Until now, happy and simdata assumed all slice times were in seconds. This will fix behavior when FSL-style (fractional TR) slicetime files are used. Behavior with .json sidecars is not changed. Non-json files are assumed to be the FSL style (fractions of a TR) UNLESS the ``--slicetimesareinseconds`` flag is used.

* (rapidtide) Tweaked mask checking logic to address a bug introduced by despeckling changes.
* (histtc, histnifti) Harmonized options between the programs.
* (Docker) Updated Dockerfile to fix a bug that caused automatic build to fail.

* (rapidtide) Major rethink of despeckling. Despeckling no longer causes negative correlation values when bipolar fitting is not enabled, and voxel parameters are only updated in a despeckled voxel if the correlation fit succeeds. This results in better fits without mysteriously unfit voxels.
* (showxy) Bland-Altman plots can now use alternative formatting, as per Krouwer, J. S. Why Bland–Altman plots should use X, not (Y+X)/2 when X is a reference method. Stat Med 27, 778–780 (2008).
* (fingerprint) This program is now substantially more useful, working on 4D input files. Output files are more convenient as well.
* (cleandirs) Cleandirs now keeps cleaning until it runs out of old installations to remove.

* (calcicc, calctexticc) Some fixes to indexing.

* (spatialmi, calcicc) Major improvements in performance, stability, and flexibility.
* (showtc) Added support for files with large star time offsets.
* (showxy) Some appearance tweaks.
* (niftidecomp) Improved mask generation.
* (variabilityizer) New program to transform fMRI datasets to variability measures.

* (spatialmi) Added new program to calculate local mutual information between 3D images.
* (calcicc) Tool to calculate ICC(3,1) - quickly - for a set of 3D images.
* (correlate.py) Fixed the reference for mutual_info_2d.
* (package) Simplified and cleaned up release process.