com_objects.h Float handling

[gnampf1]

Float handling in com_objects.h must be revised.

• objectWriteFloat takes an int as parameter, wie scaling value*100
• objectReadFloat returns an float, but always contains value*100, so no real floating point value, but just an int
• naming of both methods is confusing, as the only apply to DPT9-groupobjects, not to real float DPTs
  Method should better be renamed to something like objectWriteDPT9, and use the real floating value as input/output, not scaled by 100 as int