erling6232/imagedata: Release 3.4.2

Added

• Added documentation on viewing.
• Viewer: Ctrl+Home/End will scroll to first/last series.
• Viewer: Ctrl+Array Left/Right will scroll one series.
• Viewer: Ctrl+Array Up/Down will scroll one row of series.
• Viewer: Toggle the hide text will affect all series.

Changed

• Series.get_roi_mask(): Return 2D mask when original images is 2D.
• Viewer: Display image text even when some attributes are missing.
• Viewer: Better presentation of window center/width when they are floats.
• Viewer: Reimplemented PageDown/PageUp to scroll one page at a time.
• Viewer: Adjusting window center/width is modified to use series min/max, not existing window. Will improve user feedback when window is unreasonable.