Store the export manifest in ModPack to allow mulitple mod packs to have
different data exported. This is necessary as the export contains the
settings prototypes needed to create a proper UI for mod settings.
For now the useLocale and useItemMetadata interfaces uses the manifest
for a default mod pack set in the master config.
Add ModPack data type with corresponding storage on the master, messages
to create, update and delete them, as well as commands to invoke them.
The ModPack data type contains a list of mods with versions and optional
sha1 hashes, and mod settings to be used.
Add the ability to manage a set of mods to be shared by the master
server to the rest of the cluster. This implements storage, uploads,
downloads, deletetion, and listing details of mods but does not actually
do anything with the stored mods.
Hornwitser