Win: Add IS_WIN8PLUS macro and disable DW_FCF_COMPOSITION for Windows 8 and higher. The method used in Vista and Windows 7 to control what is drawn as glass has adverse side effects on Windows 8 and 10. Mouse clicks on what would be "glass" passed through to underlying windows due to the use of LWA_COLORKEY to specify transparency color. Additionally the glass effect has been removed. Glass was the main reason for implementing DW_FCF_COMPOSITION so just ignore the flag on Windows 8 and higher. https://stackoverflow.com/questions/4768862/dwmextendframeintoclientarea-without-transparencykey

/* XPM */
static char * kill_xpm[] = {
/* width height num_colors chars_per_pixel */
"15 15 6 1",
/* colors */
" 	c white",
".	c #5f5f5f",
"X	c gray75",
"o	c black",
"O	c gray40",
"+	c gray70",
/* pixels */
"              .",
" XXXXXXXXXXXX..",
" XoO++++++OoX..",
" XOoO++++OoOX..",
" X+OoO++OoO+X..",
" X++OoOOoO++X..",
" X+++OooO+++X..",
" X+++OooO+++X..",
" X++OoOOoO++X..",
" X+OoO++OoO+X..",
" XOoO++++OoOX..",
" XoO++++++OoX..",
" XXXXXXXXXXXX..",
" ..............",
"..............."};