Refactoring of Delta.IDs & horizon functionality with a PrimaryKey type, needed for implementing UUID based primary keys for backends such as the appengine datastore \n Tests: at top level and if available per backend, if not then just visual
Merge pull request #186 from panamafrancis/primarykeys

Implementation of the PrimaryKey type
Prevents repl panic
Adds adding/removing using repl to docs
Implements helper to split command from arguments
Also tests the helper function (ofc...)
Update docs
Quads must end with a dot ("."), as specified in the grammar
Adds default for unknown commands
Merge branch 'quickfix_repl_commands' of github.com:bcleenders/cayley into quickfix_repl_commands