Miros

The previous, **v4.1.3**, version of miros ``ThreadSafeAttributes`` class would not protect thread-safe-attributes from race conditions when they were used with the non-atomic ``"+="``, ``"-="`` ... ``"<<="`` family of operations. (I could not get the broken code to fail in my tests, it was a review that brought the error to my attention; thank you to **Ljubomir Kaludjercic** for pointing this out to me).

To fix this issue, the deque was removed and a threading.Rlock was used with the inspect module, within a descriptor. Upon access, the descriptor checks to see if the previous line of code contains a ``"+="``, ``"-="``, ... ``"<<="`` and if so it will leave the lock active until the value is set, see [the code here](https://github.com/aleph2c/miros/blob/master/miros/thread_safe_attributes.py). The usage of this limited protection was explained and documented in the example section of [miros.ca](https://aleph2c.github.io/miros/index.html), you can see it [here](https://aleph2c.github.io/miros/thread_safe_attributes.html).

Added a **ThreadSafeAttributes** class which when inherited from will provide new
class level syntax for building thread safe attributes. At the class level you
would write ``_attributes = ['attr1', 'attr2', 'attr3']`` to produce the thread
safe attributes, ``attr1``, ``attr2`` and ``attr3``. (Under the hood these attributes
are actually properties of a small deque ring buffer of size 1.) To see more
about this feature reference the recipes section of the miros project at tag
v4.1.3 or later.

The Factory class lets a miros user build state machines within a class. Previous to this release only static methods could be registered to signals during the state construction process.

* static methods are still permitted as catch handler inputs (backwards
compatible)
* standard methods are now also permitted as catch handlers too.

* the stop method can now be called from within an ActiveObject or a Factory.

* removed code which hides exceptions within your statechart (this might unmask
bugs in your design)
* changed how miros stops active objects.
* a call to the ActiveObject stop method will not stop the active fabric
* a call to the ActiveObject stop method will kill all slave threads which
are posting events into that ActiveObject.
* after the stop method is called on an ActiveObject, the ActiveFabric will
not post events into that ActiveObject's input queue, since it won't exist
anymore.
* removed unnecessary files from pip package (doc/test...)