We have a bunch of repositories registered in `mediawiki/extensions.git` that have never been used. I don't think there is any point in keeping them:
```
for repo in BSExtendedSearch ChemPF DetectLanguage Dice GPGMail InterwikiMap IssueTracker MassMessageEmail ORES PhpTagsDebugger PlanOut ProxyListDb RawImageHandler ReorderParserPhases SMWEnrich SearchRealnames SemanticDummyEditor ShortUrlApi ValueView VideoJsPlayer ViewportMetrics WebCache WikiPinger WikibaseClient WikibaseLib WikibaseView Workflow; do echo -n "| $repo "; git -C $repo log -n1 --format="| %h | %ai | %an | %s |"; done;
```
| Status | Extension | Last commit | Last commit date | Commit author | Commit subject
|--|--|--|--|--|--
| Hidden, moved to other repo | BSExtendedSearch | e7f13d3 | 2015-06-18 01:20:53 +0200 | Christian Aistleitner | Add .gitreview |
| Read-only | ChemPF | 00d57c7 | 2015-06-15 12:11:27 +0200 | Christian Aistleitner | Add .gitreview |
| Hidden, empty | DetectLanguage | fff49d3 | 2014-09-12 09:18:36 +0200 | Christian Aistleitner | Add .gitreview |
| Read-only | Dice | 420d062 | 2012-05-21 16:25:05 +0000 | Siebrand | Merge "Add .gitignore" |
| Read-only | InterwikiMap | 082e772 | 2012-11-21 16:34:44 +0000 | Reedy | Add .gitreview and .gitignore |
| Read-only | IssueTracker | ca0867e | 2013-10-23 13:05:55 +0200 | Christian Aistleitner | Add .gitreview |
| Keep | MassMessageEmail | 57e7cef | 2015-05-05 10:24:54 +0200 | Christian Aistleitner | Add .gitreview |
| Keep | ORES | e0e3a07 | 2015-08-05 10:29:08 +0200 | Christian Aistleitner | Add .gitreview |
| Hidden | PhpTagsDebugger | 08ed5ff | 2014-01-28 12:19:16 +0100 | Christian Aistleitner | Add .gitreview |
| Read-only | PlanOut | e0b4383 | 2014-11-13 11:26:14 -0800 | Ori Livneh | Initial commit |
| Read-only | ProxyListDb | b4272d3 | 2012-08-30 23:02:29 +0100 | Reedy | Add .gitignore and .gitreview |
| Hidden | RawImageHandler | 75bac54 | 2015-04-01 13:00:12 +0200 | Christian Aistleitner | Add .gitreview |
| Read-only | ReorderParserPhases | 1701ad9 | 2014-05-03 16:55:20 +0200 | Christian Aistleitner | Add .gitreview |
| Hidden | SMWEnrich | ee87cc2 | 2015-04-24 23:42:17 +0200 | Christian Aistleitner | Add .gitreview |
| Read-only | SearchRealnames | 00c52a1 | 2013-06-02 03:08:25 +0100 | Reedy | Add .gitreview and .gitignore |
| Hidden | SemanticDummyEditor | ff7d5b4 | 2014-06-18 11:12:13 +0200 | Christian Aistleitner | Add .gitreview |
| Hidden | ShortUrlApi | d4c3236 | 2014-10-04 23:16:01 -0400 | Mark A. Hershberger | .gitreview |
| Deleted | ValueView | c96e5b3 | 2013-07-10 23:06:48 +0100 | Reedy | Add .gitreview and .gitignore |
| Read-only | VideoJsPlayer | 192092e | 2014-01-02 09:03:12 +0100 | Christian Aistleitner | Add .gitreview |
| Hidden | ViewportMetrics | adaa784 | 2014-11-20 11:08:37 +0100 | Christian Aistleitner | Add .gitreview |
| Read-only | WebCache | 27c3005 | 2014-05-22 20:24:28 +0200 | Christian Aistleitner | Add .gitreview |
| Read-only | WikiPinger | 4076623 | 2015-05-31 20:50:47 +0200 | Christian Aistleitner | Add .gitreview |
| Hidden | WikibaseClient | 6114fb9 | 2014-02-28 01:14:42 +0000 | Reedy | Add .gitreview and .gitignore |
| Hidden | WikibaseLib | f0d9a03 | 2014-02-28 01:14:51 +0000 | Reedy | Add .gitreview and .gitignore |
| Hidden | WikibaseView | 01cf625 | 2015-01-15 15:15:45 +0100 | Christian Aistleitner | Add .gitreview |
| Read-only | Workflow | 58a1df0 | 2014-01-13 11:42:22 +0100 | Christian Aistleitner | Add .gitreview |
That causes a bunch of overhead for CI maintenance and anyone having a clone of mediawiki/extensions.git