Add Changes

Too bad I apparently forgot to add a Changes file before this :/

Merge pull request #39 from bobmcn/hotfix/force-new-file

Add an option to New that will always create a new file.

Merge pull request #24 from lestrrat-go/topic/gh-23

Calculate t using time zone offsets

Merge pull request #7 from liubin/master

fix: set default maxAge by 7 days

Merge pull request #1 from lestrrat/topic/new-api

Redo the API

Use chan struct{} instead of chan bool