Token/PostaggedToken/ChunkedToken has poor serialization support

[schmmd]

There's half-completed code to serialize these as a tab separated list of whitespace separated token aspects. We also want some serialization that keeps all the aspects together.

I@0/PRP/B-NP rode@5/VB/B-VP

vs.

I@0 rode@5  \t  PRP VB  \t  B-NP B-VP

In the tab format, should the offsets be separated from the tokens?

I rode  \t  0 5  \t  PRP VB  \t  B-NP B-VP

[schmmd]

@jgilme1, @rbart I wrote down some notes from our meeting.

[jgilme1]

Use Format objects from this example 483dfdc to implement serialization on PostaggedToken/PosTagger ChunkedToken/Chunker

[schmmd]

Btw, I pushed those change to master. 5534ea4