Re-worked the panel builder and panel selection, can now build a panel based on a sample file. This method avoids having to type all the FCS text values and we can determine the number of parameters for the panel which allows the use of a pre-populated formset.

select_panel.html:
- returned json for error case doesn't have key '__all__', just append the list elements

view_project_samples.html:
- modify the select panel button to appear when showing the parameters...before it would only show if there weren't any parameter maps, but now all samples will have parameter maps, they just may not be associated with a parameter yet

create_panel_from_sample.html:
- new template to create a panel based on a sample's parameters. Simplifies the panel building process:
   - don't have to specify a site, the sample is already associated with a site
   - panel name will automatically be the sample's original file name, can modify if you want
   - we know how many panel parameter maps we need b/c it's the number of sample parameter maps
   - pre-fill the fcs text for all the panel parameters, so don't have to type it

 forms.py:
 - new forms for the panel from sample stuff: PanelFromSampleForm and PanelParameterMapFromSampleForm

 views.py:
 - new view create_panel_from_sample(), uses inlineformset_factory. Note the factory method can't go in forms.py b/c we need to dynamically set 'extra=' to the number of sampleparametermaps in the sample
 - BUGFIX: in select_panel() view, catch the ValidationErrors thrown by utils.apply_panel_to_sample()...otherwise the user doesn't the error message

 urls.py:
 - add route for create_panel_from_sample() view