This also removes the dependency of engines on the event recorder header
and API, and will make it easier to RandomSources that are not properly
registered.
This makes it possible to write
DECLARE_SINGLETON(foo);
instead of
DECLARE_SINGLETON(foo)
without causing a warning about an extra semicolon.
The extra semicolon helps some editors at parsing the C++ code.
svn-id: r54258
We need to use a namespace Common { } there to make strict C++ compilers
like clang++ and comeau happy. I also added a slight comment about why
that is needed to the macro definition and a note that you need to use
it from the global namespace.
svn-id: r48254
