New HelperProvider implementation

[Frank Budinsky <frankb@ca.ibm.com>]

Hi Guys,

Attached is a proposed new implementation for class HelperProvider. The 
advantages of this impl are:

1. It allows SDO implementations be registered as a Java Service Provider 
- 
http://java.sun.com/j2se/1.4.2/docs/guide/jar/jar.html#Service%20Provider
2. Implementations should not need to replace this impl, but instead 
simply plug in an subclass with necessary overrides.
3. I believe it's backward compatible with the previous version.

Please take a look at this impl, and let me know what you think. Maybe we 
can discuss in tomorrow's call?

Thanks,
Frank.

HelperProvider.java