Verbose mbind() Error Message on Multiple Differing Dimensions

[0UmfHxcvx5J7JoaOhFSs5mncnisTJJ6q]

Originates from pik-piam/remind2#604, discussed with @orichters and @fbenke-pik.
The idea is to have more information available in the error message for debugging. To that end, mbind() does something like a three-way-diff, noting for all dimensions that differ (relative to the first input) which elements are missing, which are identical, and which are added.

A <- maxample('pop')[c('AFR', 'CPA', 'EUR', 'FSU', 'LAM', 'MEA', 'NAM'),,'A2']
B <- maxample('pop')[c('MEA', 'NAM', 'PAO', 'PAS'),,'B1']

mbind(A, B)

# Error in mbind(A, B) : 
#   Cannot handle objects! Spatial as well as data dimensions differ!
#   Differences from first mbind() input:
#   spatial:
#       missing: `AFR`, `CPA`, `EUR`, `FSU`, ...
#        having: `MEA`, `NAM`
#        adding: `PAO`, `PAS`
#   data:
#       missing: `A2`
#        adding: `B1`

The change only affects the "Cannot handle objects!" error, so no external code that actually works.

[tscheypidi]

nice improvement

[fbenke-pik]

Could you increment the version number to a non-dev number?