Driver Capability data and documentation is inconsistent and incomplete

[runette]

Working through adding the save function to the Python interface, it has become clear to me that the available documentation AND the underlying capability flags for Driver Capabilities are inconsistent and incomplete.

I created a small Python app to tabulate the underlying Capability flags as accessed through the C API and the results look like this where "Vertex Data" for instance means the write Capability for Vertex data since there is no flag for read capability

Driver	Description	Load Mesh	Save Mesh	Vertex Data	Face Data	Edge Date	Volume Data
2DM	2DM Mesh File	True	True	False	False	False	False
XMS_TIN	XMS Tin Mesh File	True	False	False	False	False	False
SELAFIN	Selafin File	True	True	True	False	False	False
ESRI_TIN	Esri TIN	True	False	False	False	False	False
PLY	Stanford PLY Ascii Mesh File	True	False	False	False	False	False
FLO2D	Flo2D	True	False	False	True	False	False
HEC2D	HEC-RAS 2D	True	False	False	False	False	False
TUFLOWFV	TUFLOW FV	True	False	False	False	False	False
SWW	AnuGA	True	False	False	False	False	False
Ugrid	UGRID Results	True	True	False	False	False	False
NETCDF	GDAL NetCDF	True	False	False	False	False	False
GRIB	GDAL Grib	True	False	False	False	False	False
ASCII_DAT	DAT	False	False	True	True	True	False
BINARY_DAT	Binary DAT	False	False	True	False	False	False
XMDF	TUFLOW XMDF	False	False	False	False	False	False
XDMF	XDMF	False	False	False	False	False	False

Some Issues:

• The set of capabilities seem incomplete. It seems important to know what types of data can read as well as written. Also - while it seems ok to assume that "load meshes" assumes support for 2.5D meshes (i.e. meshes with either 2D or 3D vertices), it seems that there should be a flag for support of 1D meshes. I will probably submit a PR proposing some changes when I can get it together,

• The actual contents of Capability flags seems ... un-expected. As an example - the flags say that the Ugrid driver cannot save any of the forms of data while in other correspondence it seems that it can save volumetric data? I think that there needs to be review of the flag settings for all drivers.

• The documentation is not clear, is not consistent between the README and the docs and not consistent with the flags. I think that we need to create an automatic link between the docs and the capability flags. I can see a way of doing this using the Python bindings and will against submit a PR.