Generate Riak Search schema from Document metadata

[seancribbs]

• Detect Documents that have search indexing enabled
• Allow annotation of properties that should be indexed in Search
• Generate Search-compatible schema from Document metadata
  • Option to ignore unknown fields, or accept without additional type information
• Either:
  • Rake task to apply Search schemas via search-cmd (useful in deployment as well)
  • Automatic fetch/comparison/update of stored schema via a client interface (TBD)