Improve the flow for setting/changing/resetting User password to make
it more secure.
1. Modify `User.resetPassword` to create a token scoped to allow
invocation of a single remote method: `User.setPassword`.
2. Scope the method `User.setPassword` so that regular tokens created
by `User.login` are not allowed to execute it.
For backwards compatibility, this new mode (flow) is enabled only
when User model setting `restrictResetPasswordTokenScope` is set to
`true`.
3. Changing the password via `User.prototype.patchAttributes`
(and similar DAO methods) is no longer allowed. Applications
must call `User.changePassword` and ask the user to provide
the current (old) password.
For backwards compatibility, this new mode (flow) is enabled only
when User model setting `rejectPasswordChangesViaPatchOrReplace` is set
to `true`.