Closes #374: Use unitless constant for transit network density
Move scenario subviews to their own subdirectories

Also deletes scenarios-service and paves the
way for it's replacement:
ScenarioManager

This is it's own commit just to separate the boilerplate
from actual changes.
Refactor scenario-service into Manager+Model

Each model now has two classes:
Model: The actual model definition, in most cases just a $resource
Manager: A class to cache individual instances of Model, plus
            provide helper methods for caching/filtering

trip-model.js is unimplemented, and is just a placeholder
with all of the old prototype code.

Moves isReverseView from service back to controller, since
    it really is controller level code

Moved the scenario retrieval functions in scenario-controller
    to list-controller since we don't really need this data
    anywhere else

The scenarios views should work up through routes. Any view past
that will likely crash. But thats ok, we have cards to fix it.

FIXME: The /gt/scenarios/<db>/routes endpoint returns human-readable
        string for routeType, need integer.
Use routeType id on scenario endpoint, switch camelCase

Also updates routes-controller with scala endpoint changes
Bugfix: Scala CreateScenario fails without stops_routes()

Calls stops_routes_function.sql during Scenario Database
creation.
Update bower to use angular 1.3.1

This is a breaking change and will require the removal
of the bower_components directory + a 'bower install'
Disable sample_period on new view if already exists
Bugfix: list controller updateHeight event

Must use $scope.$emit to bubble events up the scope
since the directive is on a parent scope.

Previous use of $scope.$broadcast saw these events never fire
because they were being fired down to child scopes.
Add scenario new-success view

FIXME: Does not update name/description of existing scenarios
Use GeoTrellis' unioned method

GeoTrellis now has a union method; the import
for CascadedPolygonUnion in GeoTrellis broke
this set of code since the imports conflicted.

See: https://github.com/geotrellis/geotrellis/pull/906

This commit fixes that and uses the new unioned
method in GeoTrellis.
Merge pull request #411 from WorldBank-Transport/feature/fix-geotrellis-union

Use GeoTrellis' unioned method
Make Indicator controls actually update tiles
Remove duplicate stops coverage indicator
Merge pull request #407 from WorldBank-Transport/feature/scenario-create

Feature/scenario create
Merge pull request #412 from WorldBank-Transport/feature/scenarios

Feature/scenarios
Attach buffer geometries to certain indicators
Render buffers in Windshaft.
Remove giant post-refactor comment block
Fix double import problem after Geotrellis update.
Merge pull request #410 from WorldBank-Transport/feature/buffers-on-map

Buffers back on map