Send wl_surface.{enter,leave} to cursor surfaces
Test plan: setup a scaled output, spawn gnome-calculator
. Cursor should be scaled too (and not blurry).
weston-terminal
doesn't send a scaled cursor, so its cursor is just scaled up (same behavior on Weston).
I changed rootston cursor size from 16 to 24 because the default theme doesn't have 16x16 cursors and fallbacks to 24x24 (that caused issues when loading the theme with a scale factor of 2).
Fixes #471 (closed)