Fix big spot painted with full pression in first click after opening dynamics popup (or any other popup)

[dacap]

It looks like when we configure the Dynamics dialog to change the brush size with the pen pressure, after clicking the canvas it paints a big spot (brush to full size) in the first click. Not sure if this is an issue in specific brands but I think we were able to reproduce it in Wacom and XP-Pen.

Reproducible on Windows, Aseprite v1.3-beta4

[dacap]

Fixed this issue with aseprite/laf@565e6bb

There where some problems receiving WT_CSRCHANGE messages after switching from the dynamics window to the main window, that reset the pointer type to 0 and made us ignore the pressure parameter.

Probably we have fixed other issues with the Wintab API, but we'll not know until we finally release this version, e.g. changing WT_CSRCHANGE with WT_PROXIMITY information to update the pointer type/cursor from pen to eraser.