TypeConverter should trim before conversion to things that are not Strings

For a simple struts2 application, when you pass in parameters that are not "Strings" for example Longs or Enums the Xwork2 TypeConverter (and Struts2's handling) needs some work.

Issues:

• numeric values are not properly parsed if they have space characters
• enum values are not properly parsed if they have space characters
• ideally some exception would bubble back up in the form of an ActionError

Attached (in comments) is a simple controller and test case using HTMLUnit to demonstrate the issue. Even with the following logger settings, no errors are visible:

log4j.logger.org.apache.struts2=TRACE
log4j.logger.com.opensymphony.xwork2=TRACE