Volume caching
Added stats
Added schema definition for cache
Added documentation to the volume cache manager
Fixed stats for tests
removed unecessary test file
Fixed payload schema
Added scope checking for volume caches
Added GC for volume caches
Fixed indentation
Adjusted stat names for cache hit/miss
Added generator support for volume cache
Cache names cannot contain custom delimiter.
Unique ids will be used for cache key names
Added tests for using the cache between tasks
Merge pull request #49 from gregarndt/cached_folders

Cached folders