Merge pull request #1 from SantanderMetGroup/stable

Stable
Change in input for new grid definitions

The old interface composed of two arguments, one for X and one for Y, has been replaced by a list with components X and Y, so the output of getGrid can be directly passed to loadMultiField, for instance
Minor change in getGrid output list
Minor change in error message
First version of loadMultiField is operative

Loads several predictors from the same dataset for a common spatiotemporal domain
loadMultiField: Bug fix and other minor changes
Minor enhancement

@importFrom abind abind instead of @import abind
New plotting capabilities for multi-fields
Minor enhancement

in loadMultiField, @importFrom abind abind
@importFrom asub abind in plotMeanField
Bug fix in plotMeanField

Object 'mat' defines the plotting window layout, but I accidentally deleted the line before latest commit
Documentation update
NAMESPACE update
Minor improvements in loadMultiField

Also r-oxygen header completed
Horizontal legend in plotMeanField

Allows better visualization and does not cut the numbers
Improvement in on-screen error message

Indicates explicitly the name of the variable not found, and provides instructions on how to check correct naming
Bug fix in interpolation method choices

Other minor improvements
Minor changes
New getGrid definition
New internal function for multi-panel plotting