Add vCard import

[xet7]

Moved to here from phildini#28

From @phildini

Trickier, I think? vCard can be a single or multiple format.

From @paulproteus

If I recall correctly, vCard is a bit of a mess as a standard, with
"postel's tarpit" meaning that there are many variations that software
generates that violate the spec that software "has" to accept anyway.

This package looks sane: https://pypi.python.org/pypi/vobject

From @phildini

vobject hasn't been updated since 2009 and has no python3 support.

I think I'm ok just pulling a few fields out of the vCard soup, but being explicit about what fields those are.