Provide less verbose output in `summary.foo` for ordinations

[gavinsimpson]

@tpoisot comment on Twitter how verbose the outputs from some summary methods are for ordination models. These don't so much as summarise a fit but provide detailed output including lots of axis score data.

I copied vegan when writing summary() methods for my cocorresp pkg and am not changing those because the verbosity of output just isn't useful to anyone.

Would anyone freak out too much if I took a look at vegan's summary methods for ordination objects and propose changes that would shorten them?