Merged in NRAO changes


git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21433 6afa274c-0927-0410-9b47-a1284d797885
Fixed various typos and warnings generated by newest clang and g++


git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21434 6afa274c-0927-0410-9b47-a1284d797885
Fixed remaining compiler warnings

git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21435 6afa274c-0927-0410-9b47-a1284d797885
Only look for GSL if told so


git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21436 6afa274c-0927-0410-9b47-a1284d797885
Fixed doxygen documentation errors

git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21437 6afa274c-0927-0410-9b47-a1284d797885
Fixed a few more Doxygen warnings


git-svn-id: http://casacore.googlecode.com/svn/branches/nrao-nov12@21438 6afa274c-0927-0410-9b47-a1284d797885