Refactoring: dispatch "core" package modules into structs and utils, as it does not have a lot of sense anymore.

bonobo/core/__init__.py

@@ -1 +0,0 @@
-""" Core required libraries. """

bonobo/execution/node.py

@@ -3,15 +3,15 @@ from queue import Empty
 from time import sleep
 
 from bonobo.constants import INHERIT_INPUT, NOT_MODIFIED
-from bonobo.core.inputs import Input
-from bonobo.core.statistics import WithStatistics
 from bonobo.errors import InactiveReadableError
 from bonobo.execution.base import LoopingExecutionContext
 from bonobo.structs.bags import Bag
+from bonobo.structs.inputs import Input
 from bonobo.util.compat import deprecated_alias
 from bonobo.util.errors import is_error
 from bonobo.util.iterators import iter_if_not_sequence
 from bonobo.util.objects import get_name
+from bonobo.util.statistics import WithStatistics
 
 
 class NodeExecutionContext(WithStatistics, LoopingExecutionContext):

tests/structs/test_inputs.py

@@ -19,8 +19,8 @@ from queue import Empty
 import pytest
 
 from bonobo.constants import BEGIN, END
-from bonobo.core.inputs import Input
 from bonobo.errors import InactiveWritableError, InactiveReadableError
+from bonobo.structs.inputs import Input
 
 
 def test_input_runlevels():

tests/util/test_statistics.py

@@ -1,4 +1,4 @@
-from bonobo.core.statistics import WithStatistics
+from bonobo.util.statistics import WithStatistics
 
 
 class MyThingWithStats(WithStatistics):