NB 7.2 HR integration review request: #205380:copylibs doesn't support the "rebase" attribute

Description:
http://netbeans.org/bugzilla/show_bug.cgi?id=205380

Due to problems caused by invalid jar paths on Class-Path attribute in MANIFEST.MF the rebase attributed was added into CopyLibs ant task.
Both library and build-impl.xml are updated. Users with the per-project libraries have a copy (snapshot) of CopyLibs stored in the project.
This causes that the build fails when the project's build-impl.xml is updated. While user can resolve the issue by reimporting CopyLibs
the automatic fix of the problem seems to be desired.
The fix adds a hook into J2SEProject's ProjectOpenHook which updates the per project copy of CopyLibs when it has smaller version than the
global one. It also adds a property support for per project libraries (LibraryImplementation3).

Impact assessment: Affects old project with per project libraries.

Risk assessment: Risk low: It affects only project with per project libraries.

The fix has been reviewed by Jan Lahoda

Changeset:
http://hg.netbeans.org/jet-main/rev/325db673e9ca

Thanks for the review,
 Tomas