Keep history in a history file


git-svn-id: http://casacore.googlecode.com/svn/trunk@21414 6afa274c-0927-0410-9b47-a1284d797885
Applied patch given an googlecode issues


git-svn-id: http://casacore.googlecode.com/svn/trunk@21415 6afa274c-0927-0410-9b47-a1284d797885
Fixed problem for LOFAR Cobalt where attribute could have > 4000 values


git-svn-id: http://casacore.googlecode.com/svn/trunk@21416 6afa274c-0927-0410-9b47-a1284d797885