[OJS.de - OA-S II - ap 3: OAI interface] necessary metadata framework improvements
*8015* Introduced file loader base task class

Conflicts:

	locale/en_US/admin.xml
[OJS.de - OA-S II - ap 5: metrics API] metrics table
[OJS.de - OA-S II - ap 6: default metric type] implement
[OJS.de - OA-S II - ap 8: tests] make requests easier to test