Solved multi-thread problem

git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21318 6afa274c-0927-0410-9b47-a1284d797885
Improved previous fix

git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21321 6afa274c-0927-0410-9b47-a1284d797885
Incorporated NRAO changes


git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21322 6afa274c-0927-0410-9b47-a1284d797885
Improved USE_OPENMP and USE_THREADS
Added USE_BOOST (for CountedPtr)


git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21323 6afa274c-0927-0410-9b47-a1284d797885
Removed warnings given by clang++


git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21324 6afa274c-0927-0410-9b47-a1284d797885