- add Tensor operators +,-,*,/
- add __repr__ funciton to Tensor
- add operator constructor to each python binding
- fix identity_op Base class declaration in binding

- Move code definition in an external cpp file in src directory
- Remove InChannels, OutChannels, NbChannels from the list of attributes as they are only used for creating the associated Producer. They are kept as parameters of the Operator factory function to continue creating Weight and Bias Producers automatically. The number of in/out channels is now based on the Weight parameter
- 'Conv_Op::inChannels()', 'Conv_Op::outChannels()', 'ConvDepthWise::nbChannels()' functons added

- check includes
- move template functions to source file for BatchNorm and AvgPooling
- remove end-of-line spaces
- change log binded functions name convention from CamelCase to snake case