ENH: make wradlib aware of its version

[kmuehlbauer]

make wradlib aware of its version ,adapt setup.py, wradlib/init.py and doc/source/conf.py from pyart, add version and date to doc

This can go with issue #8 , its somehow related to python2/3. Adapted setup.py with versioning applied.

[kmuehlbauer]

This needs to be merged to test deployment and versioning.

[heistermann]

This PR involved to modify __init__.py, adding

from .version import git_revision as __git_revision__

When I try to import wradlib, this line throws an exception:

ImportError: No module named version

I don't have any idea about this module...is this some Python2/3 issue?

[jjhelmus]

You need to trigger wradlib's build step which creates the version.py file. Either use python setup.py install and changing directory so you do not pick up the source directory, or use python setup.py build_ext --inplace to do an in-place build.

[kmuehlbauer]

@jjhelmus Thanks, I just started to write...

[heistermann]

Thanks!