* make offline-reporting infrastructure more generic
* add a listener-trait for watching when the timestamp has been set
* prevent inclusion of empty offline reports
* add test for exclusion
* generate aura-offline reports
* ability to slash many times for being offline "multiple" times
* Logic for punishing validators for missing aura steps
* stub tests
* pave way for verification of timestamp vs slot
* alter aura import queue to wait for timestamp
* check timestamp matches seal
* do inherent check properly
* service compiles
* all tests compile
* test srml-aura logic
* aura tests pass
* everything builds
* some more final tweaks to block authorship for aura
* switch to manual delays before step
* restore substrate-consensus-aura to always std and address grumbles
* update some state roots in executor tests
* node-executor tests pass
* get most tests passing
* address grumbles
Bastian Köcher