Make the direct use of `TimedArrays` in Python (e.g. not in code strings) have semantics that are consistent with the interpretation during a simulation run. Closes #345
Merge pull request #346 from brian-team/fix_345

Make the direct use of `TimedArrays` in Python consistent with the interpretation during simulation
Make `Group.get_states` with `units=True` actually return units...
Fix the interpretation of multiple stochastic variables in explicit state updaters. Closes #330
Allow explicit state updaters to have additional custom checks
Have the milstein stateupdater check that the noise is diagonal
Do not fail with a KeyError if an expression does not refer to all noise variables
Further fixes for the multiple stochastic variables situation
Make tests pass again, slightly refactor the `ExplicitStateUpdater` code (but `_stochastic_part` and `_non_stochastic_part` are still very redundant)
Add some basic tests for stochastic state updaters and multiple stochastic variables
Add a slightly more elaborate test for multiple noise variables where the random number generation is replaced by a constant value
Re-introduce a test fix, mark the more complex SDE tests as "long"