NetCDF_CF and NetCDF_CF_Gridded now hidden from view. NetCDF_Gridded is now the new name for NetCDFGriddedByVariableName, and the default for *.nc files. Gridded output files nolonger prefixed with 'cis-'.
Removed references to NetCDFGriddedByVariableName and NetCDF_CF_Gridded in documentation examples. Also removed 'cis-' prefixes where appropriate.
Reimplemented some tests for xglnwa and xenida files using NetCDF_Gridded reader.
Fixed spelling of 'valid_1d_variable'
Safer method to remove the 'cis-' prefix - now is only removed if it is genuinley the first prefix to the file.
Updates for CloudSat product. Signature is now more general, and vdata variables with height data can now correctly be plotted. Tests and documentation are also updated.
Fix to prevent gridded-gridded colocation trying to colocate with anything other than dim coords.

Also fixed gridded colocation example images which were back to front for nn and li.
Removed access to private instance variable in Iris that is to be depreciated in Iris 1.7.0. To make GriddedData from a cube the class is now changed instead. Aggregator now makes use of the make_from_cube method.
Merge remote-tracking branch 'origin/devel' into colocationreorg

Conflicts:
	jasmin_cis/aggregation/aggregator.py
Further fix related to that for Trac #404 in bcebe3c7..: For nn and li colocation of gridded data to ungridded sample points, omit sample point coordinates that are not dimension coordinates of the grid.
Added moments kernel and support for it in GeneralUngriddedColocator.
Removed DefaultColocator, AverageColocator, DifferenceColocator and DebugColocator: first two replaced by GeneralUngriddedColocator; others no longer suported. Removed full_average kernel, replaced by moments kernel. Added alias classes for nn_* kernels. Made DummyColocator usable for ungridded to ungridded colocation.