Changeset 3725 for branches

These changes allow now to run the routing (in its regional version) on non regular lat/lon grid. To achieve this the following modifications were made :

• Proper treatment of the domain boundaries for ORCHIDEE and the routing.nc file.
• coordinate based diagnostic tools.
• introduction of a large scale outflow direction for each sub-basin.
• rewrite of the routing_linkup routine.
• bug corrections.

The new methology seems to work well but further diagnostics are needed. Furthermore the code needs some clean-up more comments more severe tests. Furthermore the methodology developped here also needs to be transfered to routing.f90 so that the old river description file can be used as well.