v0.5.15

this release changes:

• feature: configurable shortcuts for drawing pad buttons
• improvement: input events for rate-limited devices (E-Paper/ low-frequency displays)
• improvement: reduced Svg export size
• fix: artifacts when printing
• fix: Jpeg images embedded in Pdfs were not rendered
• fix: select-all with "ctrl+a" included trashed strokes
• fix: units in settings kept resetting to "Px"
• fix: flicker when duplicating large selections