Implement PEP396 which specifies that a package should advertise its
version via __version__ attribute.
As devlib is often used as a development version directly from source,
also add a __full_version__ attribute which appends the current commit
ID to the version.
Use the __full_version__ inside setup.py
Using the wrapt module we can improve the memoize decorator. In fact, it allows
to preserve the attributes of the memoized function, such as signature,
docstring, path to the file where the function is implemented, and so on.
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
