[CF-metadata] bounds

[John Caron]

Jonathan Gregory wrote:

>(3) If 1D cells i and i+1 are contiguous, bound (i,1) should exactly equal
>bound (i+1,0). The data-writer should ensure that this is so. [At present, the
>standard does not state how contiguousness should be tested.]
>
I would prefer "equal within tolerence". if you need a definition of 
tolerence, i would use something like
     abs( (a-b)/b) < 1.0E-5

The reason is that post processors shouldnt have to preserve floating 
point to the last bitter bit. ;^}