Change name to avoid confusion with existing libraries

[damiencorpataux]

Existing python libraries (in order of complete-/awesomeness):

• PyRRD (complete objects abstraction + low-level bindings)
  https://pypi.python.org/pypi/PyRRD
  https://code.google.com/p/pyrrd/
• tw2.rrd (web rrd data visualization widget)
  https://pypi.python.org/pypi/tw2.rrd/2.1.0
• rrdpy
  https://code.google.com/p/rrdpy/
• rrdpython (tobi rrd python pseudo-binding)
  http://oss.oetiker.ch/rrdtool/prog/rrdpython.en.html
• python-rrdtool (basic higher-level objects abstraction on rrdpython)
  https://github.com/commx/python-rrdtool