Print primal type, not primal value

[oxinabox]

This helps with #146
It doesn't solve it completely.
test_rrule: muladd on Matrix{ComplexF64},Matrix{ComplexF64},Vector{ComplexF64}: is still too long.

but it is better than:

test_rrule: muladd at (ComplexF64[0.4196589978210228 + 0.06678470996838337im 0.7234983983250549 + 0.12177689554226734im 0.1444667492753262 + 0.852824421053991im; 0.0013063927651701945 + 0.07960169680989404im 0.8821340299832212 + 0.8674832432528303im 0.6399916250104181 + 0.9213673755779661im; 0.9305666542318896 + 0.028798798400179848im 0.3251285135517823 + 0.7192046410325192im 0.781878780061285 + 0.4168105129559001im], ComplexF64[0.9864502766235548 + 0.09411549814329323im 0.568369797143335 + 0.18162232839781756im 0.12073688021595674 + 0.7876976518594212im; 0.3676544278610394 + 0.6476833738007652im 0.1586107649093702 + 0.38256907364175685im 0.5222205873096579 + 0.8615607135061307im; 0.6912473558928405 + 0.7726403047910935im 0.1905994727310476 + 0.35635205426707417im 0.6520669089606099 + 0.728078055403989im], ComplexF64[0.8792337248319595 + 0.7147800890174674im, 0.3356474193304444 + 0.6147784569079706im, 0.15406494057687858 + 0.6214967431700242im])

[oxinabox]

Will fix doctests tomorrow