[nomaster] Revert "refactors handling of parent types"

This reverts commit 40063b0009d55ed527bf1625d99a168a8faa4124.

Conflicts:
	src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
	src/compiler/scala/tools/nsc/typechecker/Typers.scala
[nomaster] verifies compat with 2.10.0

Makes sure that the compiler understands the 2.10.0 format of super
constructor calls after the recent revert from the typemacro-compatible
format.