plugins/__init__.py: remove some unused? imports
Topic: remove duplicate import
Topic: allow specifying a commalist of topic numbers in 'remove'
Merge pull request #972 from GLolol/topic-1

Topic: remove duplicate 'import re'
Merge pull request #971 from GLolol/plugin-init

plugins/__init__.py: remove some unused imports
Topic: switch 'remove' to many instead of commalist
Topic: add test for removing multiple topics
Merge pull request #975 from GLolol/topic-remove-commalist

Topic: in 'topic.remove', allow specifying multiple topic numbers to remove