Add the properties for camel context

If we want to configure the some camel internal component such as CachedOutputStream from camel context, we can use a map of properties to do this kind of work.
With Java code
Map<String, String> properties = new HashMap<String, String>();
properties.put(CachedOutputStream.THRESHOLD, "1000");
camelContext..setProperties(properties);

With Spring configuration
<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
<properties>
<property key="the key of properties" value="the value as string"/>
</properties>
...
<camelContext>