Plugins declare their own namespace, and no longer alias themselves back

[mastacontrola]

Documentation for FOGProject/fogproject#1535 + FOGProject/fog-plugins#33, which put every plugin class into FOG\Plugins\<Plugin> and taught core to resolve it. Merge after those.

development/plugin-development.md

§7a said "stay in the global namespace", and carried a subsection telling authors that a page, hook, event, report or task in a namespace of their own must end in class_alias(__NAMESPACE__ . '\Foo', 'Foo'). Both are withdrawn.

A plugin class declares namespace FOG\Plugins\<Ucfirst-directory>; — one flat namespace per plugin, whatever subdirectory the file sits in — and needs no alias, because core reads each plugin file's own namespace declaration and maps the bare short name onto the FQCN itself.

The alias rule was worth deleting rather than restating more clearly: a plugin page that got it wrong did not declare the class its filename promised, which is an uncaught TypeError out of FOGPageManager's constructor and a bodyless 500 on every page of the site, recoverable only from a shell.

New subsections cover what replaced it:

• Discovery still works by filename — the .page.php / .hook.php suffixes are how a file gets found, so nothing moved and nothing was renamed. This is namespacing, not a PSR-4 move.
• Backwards compatible — a plugin with no namespace keeps loading unchanged. Third-party authors need do nothing.
• Two plugins, one class name, no collision — the new guarantee.
• The one place a bare name still bites — a class name your own code holds in a plain string.

The get_class($this) example is now a plugin class, since that advice is true of plugins too.

1.6/management/web/reports.md — found on the way, and separately broken

Checking that nothing else still recommended an alias turned up the custom-report example, stale for a second reason:

namespace FOG;
class Example_Report extends ReportManagement

Unqualified inside namespace FOG; that resolves FOG\ReportManagement — a name that stopped existing when core's pages moved into FOG\Pages, and which the autoloader now refuses outright rather than bridging (it logs the correct FQCN and returns). Copying the example gave a fatal, not a report.

It is now a global-namespace file extending \FOG\Pages\ReportManagement, with no class_alias, plus a note on how a report shipped inside a plugin differs.

Not done

translations/fr/development/plugin-development.md is now stale. Left untouched rather than machine-translated.