Fixing bug with netcdf_seq

+) Adding include file for exception
+) Correcting call inside a namespace

Test
+) On local
+) Passed

git-svn-id: http://forge.ipsl.jussieu.fr/ioserver/svn/XIOS/branchs/xios-1.0@508 d613d254-d18a-4304-b296-5125d4c4d670