NOTE: This commit is a prototype version of the scatterplot matrix, still some bugs to work out but basically working

view_sample_scatterplot.html:
- displays a scatterplot matrix for the parameters in a sample
- this is basically working, but there is some bug in the plotting as the center plots should only have points along a line

view_subject.html:
- added actions column for downloading the FCS file, getting a csv of the parameters, or viewing a scatterplot matrix

models.py:
- added Sample model method for getting the FCS data array...currrently limited to 1000 rows as it takes too long to parse...need to stick with pure numpy methods to keep this fast, maybe saveText()???

urls.py:
- new route 'sample_data' to get the CSV of a sample's parameter data
- new route ' sample_scatterplot' for the vew_sample_scatterplot view

views.py:
- new view 'sample_data' just provides a response containing a csv of a sample's parameter data
- new view 'view_sample_scatterplot' to render the view_sample_scatterplot.html template