* ecore.cs (ExplicitReferenceConversionExists): Made public.
(ImplicitReferenceConversionExists): Split out from
StandardConversionExists.
* expression.cs (As): We were only implementing one of the three
cases for the as operator. We now implement them all.
(Is): Implement the various other cases for Is as well.
* typemanager.cs (CACHE): New define used to control if we want or
not the FindMembers cache. Seems to have a negative impact on
performance currently
(MemberLookup): Nested types have full acess to
enclosing type members
Remove code that coped with instance/static returns for events, we
now catch this in RealFindMembers.
(RealFindMembers): only perform static lookup if the instance
lookup did not return a type or an event.
svn path=/trunk/mcs/; revision=4724
