Tests reorganized (tests/core; in future there will be tests/plugins, etc..)
Added cleanup target to makefile
Updated changelog
Added "mock" to test requirements
Updated requirements (+ descriptions)
Drafted spec of dataset configuration for geo plugins
Some more implementation skeleton for the geo plugin
Some initial documentation for core plugins
Added default settings for testing
Draft for geo plugin tests
Improved database handling (two connections, use a reserved one for turning autocommit on)
Started writing some tests for the base plugin