Padding stimuli with zeros

[mbeyeler]

Electrical stimuli should have a pad method that pads the stimulus with zeros up to a specific stimulus duration. This is useful when building your own stimuli from elementary parts. For example, shifting a stimulus by 3 seconds will make the stimulus start at 3; the t=0 data point is missing, and the end of the stimulus is also shifted. Make it so it's easy to pad it to 10 seconds total.