Corrected typo in varinfo.dat (sand_north_ variable)

[arango]

Corrected a typo in varinfo.dat when defining the metadata for the sand_north_ boundary variable. The following definition was changed from

'sand_north_'                                      ! Input
  'suspended noncohesive sediment northern boundary condition'
  'kilogram meter-3'                               ! [kg/m3]
  'sand_north_, scalar, series'
  'sand_time'
  'idTbry(inorth,idmud(i))'
  'nulvar'
  1.0d0

to

'sand_north_'                                      ! Input
  'suspended noncohesive sediment northern boundary condition'
  'kilogram meter-3'                               ! [kg/m3]
  'sand_north_, scalar, series'
  'sand_time'
  'idTbry(inorth,isand(i))'
  'nulvar'
  1.0d0

The incorrect token idTbry(inorth,idmud(i)) affected the northern boundary condition for noncohesive sediments since it was not assigned (idTbry(:,4)=0). This bug has been in varinfo.dat for awhile. Many thanks to Xiang-Ming Zeng for ​reporting this problem.

I also corrected a typo in all ocean.in input scripts when describing LtracerSrc in glossary section. This typo just affected its documentation.