hg: build-infra/jdk8: * MakeStart and MakeFinish can now extract their target automatically.

[magnus.ihse.bursie at oracle.com]

Changeset: 38ca361f31b9
Author:    ihse
Date:      2012-10-24 23:41 +0200
URL:       http://hg.openjdk.java.net/build-infra/jdk8/rev/38ca361f31b9

* MakeStart and MakeFinish can now extract their target automatically.
* Improve CheckIfFinished to cover almost all possible situations.
* Make top-level target enter/exit banners more compact.
* Improve build time summary output.

! common/makefiles/Main.gmk
! common/makefiles/MakeBase.gmk
! common/makefiles/MakeHelpers.gmk