gnu: icedtea: Update to 1.13.11.

Fixes CVE-2016-{0686, 0687, 0695, 3425, 3427}.

* gnu/packages/patches/icedtea-remove-overrides.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/java.scm (icedtea): Update to 1.13.11.
[source]: Use the patch.
[inputs]: Add libxcomposite.