This makes the interwiki map available to Lua modules. The code is
based on the API interwiki map code in core (the appendInterwikiMap
method of includes/api/ApiQuerySiteInfo.php.) Everything that the
API includes is added, apart from iw_api and iw_wikiid, which I
couldn't think of a use for from Lua modules.
Accessing the interwiki map would be useful for modules like
enwiki's Module:InterwikiTable,[1] as it would stop module writers
having to duplicate the data.
[1] https://en.wikipedia.org/wiki/Module:InterwikiTable
Change-Id: Ie8ad2582aaf5e422824f7da51714a347bb4041d1
Users are reporting disappointment that using pairs on title objects
doesn't let them see the fields available. It's easy enough to add a
__pairs metamethod to allow pairs to work on title objects, so let's do
that.
The same can be done for mw.uri objects.
For mw.message objects, we can easily enough change the implementation
to be like mw.language objects, which doesn't have this problem.
For mw.site.stats, we may as well just remove the load-on-demand feature
since it will be demanded as soon as the environment is cloned for the
first module.
Change-Id: Ie5a3b5684b2bb6c090f9994baa03977687688929
Fixed several accidental leaks to the global namespace due to missing
"local" declaration. Removed extension of the string table by mw.uri,
same justification as I5d0ddb70.
Change-Id: Iba1bf8e651d4ce05812e4a9a7a074cb6679297a0
