[WIP]Feat/total aggregation

[greyfenrir]

Each PR must conform to Developer's Guide.

Quick checklist:

• Description of PR explains the context of change
• Unit tests cover the change, no broken tests
• No static analysis warnings (Codacy etc.)
• Documentation update ('available in the unstable snapshot' warning if necessary)
• Changes file inside site/dat/docs/changes directory, one-line note of change inside