SQL Tables

SQL Tables + Some sample data
update protobuf files to new api
add new generated protobuf libraries
Merge branch 'feature/server-implementation' of github.com:mraxilus-uwe/embedded-systems-development into feature/server-implementation
make echo server actually echo messages
remove old generated protobuf files
updated tables
Merge branch 'feature/server-implementation' of github.com:mraxilus-uwe/embedded-systems-development into feature/server-implementation
add file for main communication server
add pins to database and make table drop flexible
correct spellings
add diagrams and update sql script
merge branch 'feature/server-implementation'

Conflicts:
	common/protobuf/customer.proto
	common/protobuf/location.proto
	common/protobuf/packet.proto
	common/protobuf/python/echo.py
	common/protobuf/track.proto