Allows for configuration of individual bean property values from a property resource,
i.e. a properties file. Useful for custom config files targeted at system
administrators that override bean properties configured in the application context.
Two concrete implementations are provided in the distribution:
PropertyOverrideConfigurer for "beanName.property=value" style overriding
(pushing values from a properties file into bean definitions)
Property values can be converted after reading them in, through overriding
the convertPropertyValue(java.lang.String) method. For example, encrypted values
can be detected and decrypted accordingly before processing them.