Fixes memory-leak in InputNetcdfCf

* Memory allocated when reading NetcdfCf files was not deallocated
Generalize DownscalerElevation to other variables
Bug fix and improvements to graphics2

* sort dates, offsets, locations in files. No effect if files have
  common locations in the same order.
* added -llrange
* in '-m against' only colour points that are significantly different
Added CorrectorConditional
Centering of points in CorrectorConditional
Choose below/within/above in graphics2

* Threshold metrics can show frequencies below/above thresholds, or
  within consecutive thresholds
* Improvement to '-m cond'. Center F|O point on the mean O within each
  bin, instead of the middle point in the interval. Same for O|F.
Added EDI metric
Bug fix in DiscreteConsensus

* Doesn't need to update parameters
Merge branch 'devel'