lambert grib
Support qplt.show in extest.
Merge pull request #649 from ajdawson/extest-show

Support qplt.show in extest.
Merge pull request #561 from bblay/lambgrib

Lambert conformal grib2 loading
ENH: Allow cube slicing by dimension index

Currently only coordinates can be used to slice a given cube.  Since
coordinates are not allways associated with dimensions of a cube, the
ability to specify dimension and or mix of coordinate and dimension is
added here to facilitate use.
changes made from review