2bdbe5b2ab
restructure tsLogo to allow setting a mask to be used when drawing the logo dots, as well as add an overlay icon, such as the arrow when connected to an exit node. The icon is still renders as white on black, but this change also prepare for doing a black on white version, as well a fully transparent icon. I don't know if we can consistently determine which to use, so this just keeps the single icon for now. Updates #1708 Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d Signed-off-by: Will Norris <will@tailscale.com>