Change long name of 'mask' because 'dragging' (or not) no longer relates to its meaning.
- pismmerge by variable now adds run_stats, lat, lon (if available) to merged file.
- I realized I drowned Storglaciaren a few years ago by flipping easting and northing, and this has gone unnoticed so far. Not only that, I also had gotten the projection wrong. This should be fixed now, and Storglaciaren is back to where it belongs to: East of the Kebnekaise and not in the middle of the ocean…
- massaged config file to get vol and area scaling on std out right.
Switch to Richardson iterations with the LU preconditioner for the CFBC verification test.

I hope this will take care of the nightly test failure.
Fix the "put temperature at depth" bootstrapping rule.
Fix pismmerge.

(pismmerge did not include global attributes when merging all variables.)
Add PISMTime::current_years() to ease debugging.

This method is disabled if PISM is compiled with PISM_DEBUG==0. This
is intentional.
Merge branch 'dev' into till-hydro-dynamics