updating single mother families, closes #69
Correctly recalculating child care center ratios, closes #68
adding source dummy to data folder
Visualization can now show two school layers at once.

https://github.com/nickmcclellan/dcaction/issues/42
Changes layer title, Closes #69
Adds close button to clear school data in one shot.
Addresses: https://github.com/nickmcclellan/dcaction/issues/53

Also some code clean up. Changed quotes to the most common quote used in the file.
Keeps all selected schools on map when zooming.
Keeps neighborhood highlighted when zooming with either the map buttons or double click.

Addresses github issue:
https://github.com/nickmcclellan/dcaction/issues/55
fix firefox svg size, fix library issue
Added getSource function.  Just prints to console for now.