Rapidtide

* (rapidtide, retroglm) Preserve the sign of the GLM fit R value (it might be useful for distinguishing arterial blood).
* (rapidtide) Fixed a bug with --dofinalrefine - now the shiftedtcs file IS written.
* (delayvar) New secret program, for secret purposes, to satisfy a question I had. More later.
* (package) Clarified that the final sLFO removal filter does NOT use a GLM (the current filter is an OLS filter)

* (rapidtide) Added option to perform regressor refinement on last pass.
* (rapidtide) Moved regressor refinement out into its own class to make things more modular.
* (refinedelay) Put in some experimental code to do multiderivative delay fits. Currently doesn't work very well.
* (tidepool) Changed default colormaps for similarity width, MTT.
* (package) Made a script to compile qt templates.
* (package) Added the ability to set value limits to some parser functions.

* (tidepool) Substantial speed improvement switching datasets.
* (tidepool) Colormap radio button is now set correctly.
* (tidepool) Mask menu label is now set correctly when restoring a loaded dataset.
* (versioneer) Updated to 0.29.
* (docs) tidepool's documentation has been updated to reflect the current state of the program.

* (tidepool) Full support for multiple concurrent datasets. Dataset loading and selection is now done through the File menu.
* (tidepool) Load additional informational maps, and somewhat more intelligently.
* (tidepool) Fixed pane loading to use all available panes.
* (tidepool) Fixed image saving under pyqt6.
* (tidepool) For the regressor spectrum, only do FFT of the portion of the regressor used for similarity calculation.

* (rapidtide) Fixed the calculation of the regressor autocorrelation width (used in estimating MTT).
* (tidepool) First working version that allows loading multiple files. Use ``--dataset DATASET1 DATASET2...``.
* (tidepool) Added new "big" template to let you see more information at once. Select with ``--uistyle big``.
* (tidepool) Pretty significant code cleanup under the hood.

* (rapidtide) Enhanced fit failure reporting.
* (rapidtide) Fixed map output type for non-float maps.
* (tidepool) Clarify how you specify the dataset name in the help text.
* (tidepool) Fixed some typos in outputs.
* (tidepool) Made some internal changes in preparation for allowing loading multiple files.