OSX package installation process with Drag&Drop

[Henri Gomez]

Following changes in bundle image, and as suggested by Mike, we
modified our installation process for OpenJDK for OS/X package

http://openjdk-osx-build.googlecode.com/files/OpenJDK-OSX-1.7-universal-20110916.dmg

It require directory /Library/Java/JavaVirtualMachines to exist
before, and it's only the case for users who installed Apple
Developper JDK preview or previous OpenJDK build.
Hope this directory, planned for JVM providers, will be created in the
future by system update.

Cheers