Annarchy

* Added a `bold` monitoring extension allowing to transform neural activity into a BOLD signal according to a computational model (e.g. the Balloon model).
* Added a ``Transpose`` projection.
* Replaced use of random package by numpy.random.
* Calling `clear()` in a notebook is fixed.
* Many improvements under the hood: code refactoring, new data structures (ELLPACK-R, CSRC), speed improvements, etc.

* Monitoring projections failed when the post-synaptic projection was a PopulationView not starting at 0.
* Bugfixes on CUDA:
* for higher order numerical methods (midpoint) the RNGs need to be drawn outside the update method.
* if a projection between spiking neurons was targeting two channels (e. g. ampa and nmda), a wrong code was generated.

* Moved the documentation to mkdocs: https://github.com/ANNarchy/ANNarchy.github.io
* Added a ``TimedPoissonPopulation`` allowing to schedule the rate.
* ``HomogeneousCorrelatedSpikeTrains`` can also take a schedule for rates and corr.
* Python 2 has been depreciated.
* Fixed bugs related to cython, colab, sympy 1.6.1.

* The ``tensorboard`` extension allows to log various infos and visualize them using tensorboard.
* The API of the ``convolution`` extension has slightly changed, check the documentation.
* Changed default behavior from the built-in Izhikevich neuron model from fast spiking to regular spiking.
* ``PopulationView.rank_from_coordinates`` and ``PopulationView.coordinates_from_rank`` now accept coordinates relative to the geometry of the popview using the ``local`` flag.
* Fixed installation on Anaconda distributions. Now works in colab with ``!pip install ANNarchy``.
* Several bug fixes (variable-dependent refractory periods, conditionals of the type "if (t==1)", SpikeSourceArray, etc).
* Improved performance with CUDA.

* MacOS compatibility.
* Bugfix on ``Projection.load()``.

* ``SpikeSourceArray`` can now receive connections (which will be ignored, but may be used to investigate plasticity mechanisms).
* Added a ``clear_all_callbacks()`` method when using every.
* Added a `CurrentInjection` population allowing to connect a rate-coded population to the conductance of a spiking population.
* Several bug fixes and improvements.