Bulk change of columns, LAST TIME.

* Add reply columns to Body
* Remove a bunch of unused columns from Message
* Update SQL tables, content read/write, etc.
* Small tweaks to app code that was not-really-using the old columns.
* Update existing unit tests for new/changed columns
* Disable TagsTests to solve a tests failure (prexisting, not caused by
    this CL)

Change-Id: Ief493796dfe219669755170d76786f91570cbb9b
4 files changed