Support owner class based access
Use functools to imitate wrapped function

This is more thorough than updating only docstring by hand. This takes
care of:

- copies __name__, __module__, __annotations__, __doc__
- updates __dict__
Abondon the use of `weakref` in `boundevent`

- weakref does not have the correct semantics for bound methods. A bound
  method should keep the object alive, as long as its alive! This is not
  the case for a weakref-powered `boundevent`
- the use of weakref enforces the target class to have the __weakref__
  attribute. Classes with __slots__ do not have __weakref__ by default.
Merge 'moredread/master' from pull request 5 by Moredread

on github: https://github.com/aepsil0n/event/pull/5
Merge pull request \#4 from 'coldfix/fix-descriptor'

https://github.com/aepsil0n/event/pull/4
Add link to Travis CI page to readme
Perform mere cosmetics in a couple of places

Only adjusts the layout of some docstrings to my subjective aesthetic
pleasing.