-CGA, PCJr, Tandy: Add video blanking, change display start latch timing, sync pulse width correction,

-PCJr, Tandy: implement vertical retrace interrupt,
-PCJr, CGA: do line-by-line video emulation,
-PCJr: support on-screen change of color modes 4medium to 16low (used by Ghostbusters booter),
-All machines: only update the video timing when needed (Jungle Hunt, others that synchronize to the video screen might profit), only resize the output window when needed, start up the video more quickly at the beginning.

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@3572

src/ints/bios.cpp

@@ -826,13 +826,6 @@ void BIOS_ZeroExtendedSize(bool in) {
 	if(other_memsystems < 0) other_memsystems=0;
 }
 
-#define RAM_REFRESH_DELAY 16.7f
-
-static void RAMRefresh_Event(Bitu /*val*/) {
-	PIC_ActivateIRQ(5);
-	PIC_AddEvent(RAMRefresh_Event,RAM_REFRESH_DELAY);
-}
-
 void BIOS_SetupKeyboard(void);
 void BIOS_SetupDisks(void);
 
@@ -1085,8 +1078,6 @@ public:
 		size_extended=IO_Read(0x71);
 		IO_Write(0x70,0x31);
 		size_extended|=(IO_Read(0x71) << 8);
-
-		if (machine==MCH_PCJR) PIC_AddEvent(RAMRefresh_Event,RAM_REFRESH_DELAY);
 	}
 	~BIOS(){
 		/* abort DAC playing */