Out spatial dim tags arguments not needed

[albertz]

#17 (comment) lead us to have out_spatial_dim as an optional arg to many functions and modules, e.g. Conv.

Maybe actually passing this is never really needed. If the user wants to verify that the resulting out spatial dim tag is as expected, he simply can do sth like:

conv = Conv1d(...)
out, out_spatial_dim = conv(...)
assert out_spatial_dim...  # whatever

This applies for many functions and modules which can be cleaned up then.

[albertz]

This is mostly cleaned up now.