Weight initialization

The tool now has an extra option (initialize_uniform_weights).
If set to w!=0, then the nn weights are set within a uniform
(-w,w). Otherwise, it uses default hardwired weight initialization.

initialize_uniform_weights is set to 0.05, per bbn paper.
Hum... I believe that If you don't make it inline method it will not compile. Why exactly this happens, I'm not completely sure. For the same reason i think you can't define inline methods in a header and leave the implementation in the cpp if you expect to use them for other cpps. Will check.