Merge branch 'dk-list-comments-by-fixes' into 'develop'

.gitignore

hive/db/schema.py

hive/indexer/blocks.py

hive/indexer/votes.py

hive/server/database_api/methods.py

hive/server/database_api/objects.py

hive/server/serve.py

hive/utils/normalize.py

.../manual_tests/list_comments_by_author_last_update_test.py

tests/manual_tests/list_comments_by_cashout_test.py

tests/manual_tests/list_comments_by_parent_test.py

tests/manual_tests/list_comments_by_permlink.py

tests/manual_tests/list_comments_by_root_test.py

tests/manual_tests/list_comments_by_update_test.py

tests/manual_tests/test_base.py