floating-point versus integer controls

[bstabler]

Integer controls behave better than floating-point controls and so we want the user to be aware of this.

@jfdman - maybe we should have a switch in the control file (roundControls=false), which would be set to false by default and throw an informative error message if the controls are not integers, but if set to true, would just throw a warning and round to the nearest integer before proceeding. We also need to update the wiki.