Integer division issue resolved

[rappakos]

The previously missing float cast in the initialization of the _expTable leads to a different effective activation function, ie., one with 2 steps:

• the first step at x=(-MaxExp) to 1.0/(1.0+exp(MaxExp)) \approx 0.0025 for MaxExp=6
• the second at x=MaxExp from 1.0/(1.0+exp(MaxExp)) to 1.0 This is essentially a step function with an effective bias.