method chaining

[tom-spalding]

chaining support would be nice

right now, we have to wrap everything

> Humanize = require("humanize-plus")
> Humanize.truncate(Humanize.titleCase("In 1998 they had this promotion for the Disney film Mulan, where they created a new sauce for the McNuggets called Szechuan sauce"), 14, "...etc")
'In 1998 ...etc'

compared to

> Humanize.titleCase("In 1998 they had this promotion for the Disney film Mulan, where they created a new sauce for the McNuggets called Szechuan sauce").truncate(14, "...etc")