animate API (and style/labels)

[jeremymanning]

to keep things consistent with the new “dictionary-based” syntax for align and reduce, should we have animate accept a dictionary? e.g. animate={'rotations': 2, 'chemtrails': False, 'precog': True, 'frame_rate': 30}

(and then throw a depreciation warning if the user sets duration, tail_duration, rotations, zoom, chemtrails, precog, bullettime, or frame_rate)

note: to keep the full API consistent, we might also want to have a style keyword argument that accepts a dictionary with the following arguments: fmt, marker, markers, linestyle, linestyles, color, colors, palette, elev, azim. (and then we'd depreciate these in future releases.)

and then also perhaps a labels keyword argument that accepts the following fields: group (rename to hue), labels (rename to names), legend, title, xlabel (new), ylabel (new), zlabel (new)

so the full plot function's first line would become plot(x, style=None, labels=None, animate=None, explore=False, show=True)

Other thoughts:

• Is explore still functional?
• Should show be part of the "style" dictionary?
• Maybe this is too extreme...I'm not 100% sure this is a good direction-- I'm just noting it as a possible way to clean up the API