Button to Fill Gaps with -9999 values

[AmberSJones]

The technicians have requested a button that would insert -9999 into gaps that have been identified by the gap filter. I don't know that this HAS to be done, but we should discuss it when we're prioritizing feature requests.

[sreeder]

@AmberSJones This is ready for testing on the nodvfill branch. the gui is a rough sketch, needs a little work before it is done.

[AmberSJones]

I cannot get any series to plot using this branch?

[sreeder]

what version of pandas are you using? there was some code that was deprecated so I tried to fix it. but it looks like I may have done that too soon.

[sreeder]

@AmberSJones reverted to deprecated version until we are ready update the library requirements

[AmberSJones]

This is looking good, but I think the form needs a little work. Let's add the text:
"This function fills any gaps less than the gap duration with a no-data value at the fill frequency."
Change the labels to be "Gap Duration:" and "Fill Frequency:"
Also, the fields on the form need to be lined up.

Furthermore- looks like the units that it is using to fill the gaps are off. i.e., I try to fill with 15 minute data and it fills every 15 hours.