- Give 'fit formula' title a h3 header tag
- Don't show the fit formula if 'NaN' if present, instead show 'fit not
  Possible'
- Add minimum of 0.6 instead of zero to avoid fit line overflow at y=0
- Format key for table headers to show the sexier names
- Add text-align center to the preview div to make 'fit not possible'
  also centered
Add title attribute to help clearify what the 'Select datasets to use' radio buttons are for
Return the reader object so we can listen for the onloadend event and recheck previously checked radio buttons
Add recheck buttons after downloading new data from server

Only bug is when you try to download data from server that is already
available, because the download_dataset just returns, but not as a
object which support the .done method and so it triggers an error. Just
need to check the object returned from download_dataset and make sure it
is not 'undefined'.

Maybe implement function to hold the checked_input and return
input_array
Add typeof check to data_download method, so if we want to download the
same dataset again, we do not lose our checked radio buttons
Update parse_csv function to avoid reading lines[0][0] if we select an empty dataset. So the alert message is properly displayed
Add emptying of div with plot options after dataset gets removed
Add comment and slightly tweak title
Improve log axes and show message when no data to plot

Make plugin for flot to generator logarithmic axes
Fix possible -999/-1 bin for histograms if it is the first value
Filter invalid values for logarithmic axes
Filter data before passing to histogram
Split filters into separate functions
Remove -999/-1 filter from jsparc.histogram
Add test data file with columns that have specific types of values
Fix data filters, they could skip consecutive error values (add `i--`
after splice)
Update included datasets

Events datasets now include data in the t_trigger column
Update docstring of flot log plugin
Fix flot log plugin

Removed custom options in previous commit.
Merge branch 'fitting'

Improve fit formula display
Improve tracking of selected and removed datasets
Add alert in case of loading an empty dataset
Add alert when no data can be plotted
Add nice logarithmic axes
Improve data filtering for error values
Update included exmaple datasets
Add test dataset