Merge pull request #4 from rburchell/master

[notifications] Remove CONFIG+=ordered.
[qmldir] Add Module Identifier Directive
Merge pull request #5 from thp/module-identifier-directive

[qmldir] Add Module Identifier Directive
[notifications] Add documentation package
[notifications] Remove Qt 4 support.

Not needed anymore, and an upcoming change is Qt 5-only.
[notifications] Use Q_GLOBAL_STATIC_WITH_ARGS.

This (unlike QScopedPointer) has proper lifetime-control, i.e. it will destroy
at the right time before libraries are partially destroyed.

This was causing crashes with some uses of the notification library.