rather thant ${prefix}/include/sgpemv2: users will
be able to use directives like "#include <sgpemv2/scheduler.hh>"
in their headers, which reduces name clashes.
- Make _mutex a protected member of Singleton, so that
inheriters can recycle it :-)
- Add exclusive access control for step_forward()
- Add two states (future and exhausted) to Request
git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@707 3ecf2c5c-341e-0410-92b4-d18e462d057c
tchernobog