SDL renderer improvements and fixes and added SDL OpenGL option;

Various performance improvements;
Fixed USB UHCI HCHalt;
Cirrus Logic CL-GD 5422/24 fixes and removed them from the Dev branch;
The Storage controllers sections of Settings now has its own corresponding section of the configuration file;
Fixed the AT clock divisors for some Pentium OverDrive CPU's;
Added the ACPI RTC status (no ACPI RTC alarm event yet).

src/sound/snd_sb.c

@@ -1207,7 +1207,7 @@ sb_pro_v1_opl_read(uint16_t port, void *priv)
 {
     sb_t *sb = (sb_t *)priv;
 
-    sub_cycles((int)(isa_timing * 8));
+    cycles -= ((int) (isa_timing * 8));
 
     (void)opl2_read(port, &sb->opl2);	// read, but ignore
     return(opl2_read(port, &sb->opl));