IcedTea6 1.6.1

[Andrew Haley]

The tarball version of IcedTea6 1.6 doesn't build correctly with --disable-plugin,
due to a bug in the way that the plugin is built, or rather a conflict between
that and make dist.  The version in Hg is fine, however.

Andrew Hughes has written a fix for the plugin build, and I'm going to respin
for 1.6.1.  Happily this respin will also pick up a jar speedups patch and
some install documentation changes.

Andrew.