Revert "Bug 1014257 - Add new fields and API for Profile data"

This reverts commit 883a2a6cce5d311f9b7b2dfc4b1230f57e08eebc.
1.0.42
Revert "Bug 1015639 - disallow underscores in usernames"

This reverts commit b56d7374a99f9d8b66d08a005cfc09ad9a960928.
1.0.43
Fix bug 1019282 - Convert `avatar`, `displayName`, and `emailHash` to proper custom getters
Fix bug 1019285 - Add migrations for `bio`, `location`, and `links`