Changed AddNamedChildScope to no longer set UnresolvedParentScope to null when it is used (this paves the way for later having multiple unresolved parent scopes and resolving them at merge time.
added description of what the while loop is doing.
Renamed TypeDefinition.Parents to ParentTypes.
Added "UnresolvedParentScopeInUse" to indicate which unresolved parent scope is currently being used to link this with its parent. The previous change (simply setting "UnresolvedParentScope" to null) introduced an infinite loop when merges occurred.
Moved "Accessibility" to NamedScope. and implemented it for:
1. Parsing -- types and methods now have accessibility when parsed
2. Merges -- the non-default accessmodifier between two types is used