* Add missing `ingroup` to class blocks (and remove from any file blocks)
as otherwise the file is indexed twice (e.g. in Doxygen) which makes
navigation on doc.wikimedia.org rather messy.
Remove duplicate descriptions from file blocks in favour of class
doc blocks. This reduces needless duplication and was often
incorrect or outdated, and helps make file headers more consistently
(visually) ignorable.
Ref https://gerrit.wikimedia.org/r/q/message:ingroup+is:merged
* Widen `@covers` tags in phpunit tests
Given all called methods are de-facto and liberally claimed, and
that we keep the coverage limited to the subject class, it maintains
the spirit and intent by listing the class explicitly instead.
PHPUnit offers a more precise tool when you need it (i.e. when testing
legacy monster/god classes), but for well-written code, the
class-wide tag is exactly what you want.
We lose useful coverage and waste valuable time on keeping tags
accurate through refactors (or worse, forget to do so).
Tracking tiny per-method details wastes time in realizing (and
fixing) when people inevitably don't keep them in sync, and time
lost in finding uncovered code to write tests to realize it was
already covered but "not yet claimed".
Ref https://gerrit.wikimedia.org/r/q/owner:Krinkle+is:merged+message:Widen
While at it, improve purposes and explainations of several mail-related
classes, and set `@since`:
- EmailNotification introduced in r22110 (1.11.0), git a6f6e04841,
later moved to a separate file in bf8810d6bc (Ic435bbdbb6).
- MailAddress introduced in r12082 (1.6.0, 1.5.7), git 5cfddf9a82.
- UserMailer converted to class with ::send in r26357 (1.12.0),
git 353f203ce2.
Change-Id: I1216781240bcfabdebf109cef8f995355db0f659
949c9c932e