Add exception catch for debug state system

	modified:   trace/net.sf.milkfish.product/Todo.txt
	modified:   trace/net.sf.milkfish.systrace.core/src/net/sf/milkfish/systrace/core/state/SystraceStateProvider.java
Refactor the header parse function

	modified:   trace/net.sf.milkfish.systrace.core/src/net/sf/milkfish/systrace/core/cache/TraceLoader.java