Merge branch 'fork/marc-vdm/major_search' into major-search

# Conflicts:
#	activity_browser/bwutils/__init__.py
#	activity_browser/bwutils/metadata.py
#	activity_browser/layouts/panes/database_products.py
#	activity_browser/ui/widgets/__init__.py
#	activity_browser/ui/widgets/item_model.py
#	activity_browser/ui/widgets/tree_view.py

Author: mrvisscher

activity_browser/bwutils/searchengine/__init__.py

@@ -0,0 +1,2 @@
+from .base import SearchEngine
+from .metadata_search import MetaDataSearchEngine