use C++11 style constructor for nested classes in ARM920T
add system interrupt aggregator
add basics on core for interrupts
add basics for irq/fiq action
fix MSR (armv5 specs are wrong), remove Thumb state change detection
add bit V to control register, bail on unsupported bits set
support writeback to SPSR on write to pc with S flag
AIC: return spurious vector on read from interrupt vector
add CPSR restore to LDM
dump cpsr/spsr in dumpState
clear SPSR on reset, otherwise garbage SPSR values will trigger aborts
add provisional exceptions support for irq