JAR_MANIFESTS can now be defined in moz.build files. However, due to
limitations in rules.mk, only 1 file may be defined at a time. In the
future, this restriction will be lifted. But first, better support for
JAR manifests in the build config must be built.
rules.mk will be updated in the subsequent conversion patch so this
patch applied alone doesn't break the build.
--HG--
extra : rebase_source : 2521d49a1731b659dd720769e4685715925be590
