Shadow cut off bug + shadow seam bug.

[bryanedds]

Both of these issues are caused by the SHADOW_SEAM_INSET value. When the light is big, say cutoff = 32.0, the value is too small to completely remove the shadow seam. And when the light is smaller, the value is too big and cuts off the shadow before the light ends!

We have a couple of options -

1. Make this a uniform value for each light.

2. Find some way to calculate an appropriate value for this based on the cutoff value in the shader.