channel double label

If the channel emission wavelength is an integer, labels based on this value should display it as an integer.

We also handle the case where the channel name looks like a double, although this may be going too far? E.g.

omero=# select name from logicalchannel where id in (3467,3468,3469,3470);
 name  
-------
 457.0
 528.0
 617.0
 685.0
(4 rows)

To test, check that NO images have channel labels that look like floats. E.g. "488.0".