Switched image array type from uint to float32

Cnms dev

Added the image_size and scan_size attributes to the Measurement Groups

Changed loops over attributes to use iteritems
Skip writing attribute if value is None

Renamed the function and changed how it is used so that it returns a list of all groups that match the input name.

Increment version

Hopefully will prevent error from uint+int=float when trying to slice windows.

Cnms dev

Fixed bug in how the AC Amplitude from the Spectroscopic Values was sliced in AC Mode

Corrected passing of kwargs to calls to figure, ImageGrid, and plot_map

Cnms dev

Now uses the first entry in unique_waves to get the name for the pixel_data value.

Small updates to docstrings

Added method to allow for the specification of an existing Guess when calling the fit function.

Small updates to docstrings

Added method to allow for the specification of an existing Guess when calling the fit function.

Updated mock list

Loop parameter extraction added
Hopefully fixed documentation