Fix incompatibility with Python 3 using //
Fix incompatibility with Python 3 using //

Add python 2 and 3 compatibility by using the floor division operator '//'.
Cf. https://docs.python.org/2/whatsnew/2.2.html#pep-238-changing-the-division-operator

garyfeng/pybrain,samstern/MSc-Project,garyfeng/pybrain,pybrain/pybrain,pybrain/pybrain,pybrain/pybrain,garyfeng/pybrain