The application name and URL was defined several places in the code,
and the name was not written exactly the same everywhere.
By using the same constants everywhere, consistency is obtained.
Add -V command line option (and --version as an alias) to
both wireviz.py and build_examples.py that show version number.
Move the version number from setup.py into __init__.py to access
the same version number specification from all files needing it.
This solves part 4 of issue #167.
There are hard copies of the graphviz and pyyaml dependencies included
in the repo. Remove these.
Sort out installation and dependency handling by writing a functional
setup.py script. Rename top level documentation. Refactor wireviz.py
slightly to allow it to run as an installed script.
# Conflicts:
# src/batch.py
# src/wireviz/batch.py
# src/wireviz/build_examples.py
