Defaulted the Mississipi page selects as requested.

Added code to toggle the sites layer on and off via the Toggle Sites
button. Changed the way the flow lines are added to the map. These are
now added at page rendering and is done before the sites layers are
added. Using setVisibility on layers to turn them on/off.
Modified the maxExtent and restrictedExtent to zoom in to the
Mississippi basin.
Set maxResolution so that the map can't be zoomed out past the initial
extent.
Added download.js to the list of files excluded from testing. This
prevents a console error from being logged when tests are running.
The service to retriev MRB pie chart data now performs the query as case
insensitive so that the client doesn't have to worry about the case of
the parameter values.

Modified the client service call to use split the parameter type by
underscore and only use the last part of the parameter type to retrieve
the pie chart data.
Legend tweaks - Added percentage to legend and out of pie chart,
displayed percentage to 1 decimal spot and put in padding between legend
elements for readability.
The load filters are now also tied to the Contribution display pie
charts.
Fixed ContributionDisplay test.
Merge pull request #268 from cschroed-usgs/master

Adding new variable with reasonable default.
Merge pull request #266 from mbucknell/NAWQAAN-330

Nawqaan 330
Fixed merge conflicts with NAWQAAN_330
Further fixing of merge conflicts and tweaked the position of the right
pie charts legend placement.
Work in progress.
Merge pull request #267 from mbucknell/NAWQAAN-329

Nawqaan 329
work in progress
A couple of tweaks to the pie chart legend to show percentages on the
exception cases and to increase width.
Merge branch 'master' of github.com:USGS-CIDA/nar_ui into NAWQAAN-329
Merge pull request #270 from mbucknell/NAWQAAN-329

Nawqaan 329
Approaching correct tree structure.
Put percentage sign after percent numbers in legend. This required that
the legend box be a little wider.