With corresponding change in the ParaView level caller, this eliminates
this Catalyst warning:
vtkPVTrivialProducer (0x51724d0): Requesting time 9.6 but only 9.6 is available

and the values in the parameter are now as exact as they can be
in text form. Note also that the filenames are changed in spec A
output. As I recall the formatting was done for the original javascript
viewer client which couldn't handle precise numbers or perhaps filenames.
No one is actively using or developing that project anymore so this
change is fine.