#31 System property access does not handle exceptions

[Anonymous]

In a couple of places system properties are accessed
without "SecurityException" being handled.

In some environments (e.g. Applets) this means some
WSDL4J functionality is unusable.

The affected files are:

* src/com/ibm/wsdl/util/StringUtils.java
* src/com/ibm/wsdl/util/xml/DOM2Writer.java

[Nobody/Anonymous]

DOM2Writer.java with exception handling for system property access