ILogger interface added

* ILogger interface extends ILoggerBase and ISuppress. At the moment, it
is not CLS compliant because of the V1 interface methods.
* ILoggerBase exposes the basic Log() methods.
* ISuppress interface added. It contains the Swallow() and
SwallowAsync() methods definitions. Provides an interface to execute
System.Actions without surfacing to the calling method any exceptions
raised for that action.