renamed TokenList.tokenList -> TokenList.tokens
Merge branch 'tokenlist-rename' into 'master'

Tokenlist rename

This renames TokenList.tokenList to TokenList.tokens. This avoids repetition (i.e., tokenList.tokenList) which can look a bit confusing.
addressed issue #8
Merge branch 'timeml-struct' into 'master'

Timeml struct

This addresses issue #8, creating a TimeML struct to prevent (current) bloat in Situation and allow (future) growth.

The TimeML struct doesn't have a UUID; should it? (I don't think so.)

@mthomas I'll leave this to you, since it's another breaking change.