Improved documentation of Manager class
Added `data` directory to default blog data files
Added local data variable to packages
Added data path to blog interface
Updated Package Manager to load and save package data
Triggered package data save at build completion
Documented package data functionality
Re-enabled "pretty" JSON output
Fixed issues with File System directory creation
Supported setting default data array in packages
Merge branch 'refs/heads/feature/package-data' into develop