Ruby: don't raise if ObjectPath key not found, return nil
Ruby: Implement RAISE_IF() to raise proper exception on error
Use correct type when assigning NULL to a property

Using CMPI_null type for a NULL value will not be accepted and raise a
type error. However, using a NULL value together with the original
property type works.
Gemspec: add license, fix version deps
Add RCErr... classes to transport CMPIStatus error as exception

CMPIStatus contains rc code and message, reflect this in the exception
classes.

Use the exception classes in 'raise' statements

Add Cmpi.rc_to_exception to convert an rc code to an exception class
Fix _raise_ex for Ruby to raise a real exception with full CMPIStatus data
Capture Ruby exception and extract CMPIStatus information from it

Use this to report proper CMPIStatus to the CMPI caller
Update to 1.0.0