Removed obsolete variable in TabulatedAtmosphere (Issue #740)

git-svn-id: file:///srv/svn/repos/tudat/trunk@546 ac7aa084-b6da-11df-bf42-7fac39f0224f
Updated initialization of TabulatedAtmosphere to be RAII (Issue #740)

git-svn-id: file:///srv/svn/repos/tudat/trunk@547 ac7aa084-b6da-11df-bf42-7fac39f0224f