* src/vte.c: Finish implementing window-manipulation sequences.  Rename signals
	to be more consistent.  Add thin wrappers for emitting signals, and use
	them everywhere.  Support pangox even when XFT isn't available.  Try to
	provide bold text again.  Add signals for most of the window
	manipulation control sequences.  Implement device-status-report and
	dec-device-status-report.  Clamp location values in sequence_handler_cm
	to the dimensions of the terminal window so that resize(1) will work
	right.
* src/caps.c, src/caps.h: Export definitions of VTE_CAP_CSI and friends.