* don't omitempty on description
* don't omitempty on any fields
* add ms to timestamp format
* don't omitempty on text_url
* rearrange attachment fields a bit
* just give URL again as attachment text url
* update tests
* fix accidental replace
* move caption sanitization -> sanitize.go
* use sanitizeplaintext rather than removehtml
* rename sanitizecaption to sanitizeplaintext
* avoid removing html twice from statuses
* unexport remoteHTML
it's no longer used outside the text package so this
makes it less confusing
* test instance PATCH
