v0.6.0-p0

API-breaking change: Increase dimensionality of tensors from 3 to 5 (needed for future development, like LSTMs and TimeDistributed):

• tensor3 -> tensor5
• shape_hwc -> shape5
• tensor3::get_yxz -> tensor5::get
• tensor3::set_yxz -> tensor5::set

Feature:

• Enable dense layers for non-flattened input tensors.

Fix:

• Safeguard softmax implementation against NaNs.