array.tsv(), closes #279

[odino]

Arrays can now easily be formatted as TSV / CSV content:

array.tsv()
array.tsv(",")

Here are some samples:

⧐  [["LeBron", "James"], ["James", "Harden"]].tsv()
LeBron	James
James	Harden

⧐  [{"name": "Lebron", "last": "James", "jersey": 23}, {"name": "James", "last": "Harden"}].tsv("\t", ["name", "last", "jersey", "additional_key"])
name	last	jersey	additional_key
Lebron	James	23	null
James	Harden	null	null

There is some complexity in this function due to the fact that
we have to support custom headers, as well as the fact that we
can both format arrays of objects as well as hashes.