WISH: kick out xpm.C, replace by pixbuf
DUMB: support tex fonts
+TODO: rxvtd failing to enter cwd of rxvtc leads to crash due to free(this), Gentoo #143985
TODO: fix crash because strwidth returning -1 in selection-popup in LC_ALL=C
- give proper diagnostic when RXVT_SOCKET is too long instead of
corrupting the stack (patch by exg).