Add extensible user ID change support

[Steffen Hoffmann]

This is the consequence of successive code reviews after creating #10900, #10901 and #10902.

This way the functionality will gain independence of 3rd-party support, that may never be offered anyway. At least within the mandatory 14 day period there was no reaction from any author/maintainer of the hacks that the aforementioned ticket have been filed against.

Meanwhile basic support code has already been published in changesets [12700:12702] and [12706].

[Steffen Hoffmann]

Note that the term 'user ID' change(r) has been coined do set it apart form 'username'. Maybe in the future this could become separate things, if Trac would introduce a unique ID i.e. within the ​t:wiki:GenericTrac concept, so I decided to not focus to much on the user-visible string right from the start.

[Steffen Hoffmann]

(In [12736]) AccountManagerPlugin: Add optional user ID changer components for other plugins, refs #10900, #10901, #10902, #10944 and #10945.

In addition to VotePlugin (supported by RenameTracUsersScript too) support for

• AnnouncerPlugin > 0.12.1
• ScreenshotsPlugin (all versions)
• TracFormsPlugin > v0.2

is provided within this plugin.

With the publication of this code the requests for feedback are almost obsoleted, even more, because non of the pre-existing solutions provided the coverage and extensibility, that is offered now within this plugin.

[Steffen Hoffmann]

See 24 Trac db tables changing right on your user ID change command by just filling both, the 'Username' and the new 'New username' fields in the users (accounts) admin panel:

[Steffen Hoffmann]

Feedback on user ID change request with all change components enabled, including other supported plugins

[Steffen Hoffmann]

(In [13054]) AccountManagerPlugin: Added flexibility for user ID change support, refs #10945.

New options permit

• migration to existing accounts - found to be essential for users with write-protected password stores, for setups of multiple Trac environments with shared password store(s) or as workaround for missing password reset
• preserving passwords in general for users in SessionStore or specifically when migrating to an existing account (for users in any password store)
• retaining login data of previous account - again essential for migrating one user ID in multiple Trac environments with shared password store(s)

Special processing of Trac db table session_attribute has been required, replacing the corresponding user ID changer component.

[Steffen Hoffmann]

(In [13055]) AccountManagerPlugin: Default password password must be non-empty, refs #10945.

Fixing a critical implementation issue, where on user ID change the new account has been created with empty password, and subsequent password reset would have added an alternative random password instead of replacing the initial password due to prior improvements of the password reset procedure.

[Steffen Hoffmann]

(In [13056]) AccountManagerPlugin: Calculate 'keep_passwd' properly, refs #10945.