diagrams: cosmetic formatting of cpp diagram

- link up the meta-data settings factories with workflow and formatter
  facade
- minor tidy-ups around the path spec area
agile: backlog improve errors in dia objects
agile: backlog add support for spaces in template types
cpp: regenerate from latest diagram

- rename flat name builder to identifier name builder
agile: update add support for formatter and facet dependencies
agile: backlog consider adding support for inline hashing
agile: backlog consider a more selective hashing generation