updates steerpyr behavior

[billbrod]

Updates behavior of the SteerablePyramidFreq to match the implementation of plenoptic (plenoptic-org/plenoptic#305 and plenoptic-org/plenoptic#306):

• warn the user about imperfect reconstructing when initializing pyramid with an (odd-sized image) or (order=0 and is_complex=True).
• raise ValueError if height, order, or twidth are given incorrect values.
• raise ValueError if height is negative

Note that we don't raise such warnings for SteerabePyramidSpace here because the spatial-domain implementation cannot be complex, and its reconstruction is not perfect anyway (and the errors are approximately the same magnitude when using odd- or even-sized images).