openjdk-6 and openjdk-7 multiarch installable

[Matthias Klose <doko@ubuntu.com>]

openjdk-6 and openjdk-7 are now multiarch installable, unfortunately only on 
distributions having a dpkg supporting these (Ubuntu natty and oneiric).  So you 
can have now both a i386 and amd64 jvm installed on amd64, and you could install 
the i386 jitted jvm on ia64.  It is implemented by having the jvm installed into

  /usr/lib/jvm/java-1.X.0-<deb-arch>

Different directories per architecture are currently necessary:

 - the timestamps in jar files differ (Fedora did solve this by
   repackaging the all jar files and resetting the timestamps for
   every file, so that the jar files are the same across archs).

 - some jar files differ, most notably rt.jar (does somebody want
   to address this issue?)

 - the wrappers are architecture dependent.

The path /usr/lib/jvm/java-6-openjdk isn't valid anymore.  It currently only 
contains common jar files.  The config file /etc/java-6-openjdk/nss.cfg is gone, 
and replaced by nss-<arch>.cfg. I plan to add the symlink 
/usr/lib/jvm/java-1.6.0-openjdk to the default-jre-headless package (this is not 
multiarch installable anyway).

  Matthias