Added MeasurementRoutine as a nested Measurement model

Updated ItemsWithQuantities to work with MeasurementRoutine
Replaced ColumnViews HABTM with polymorphic HMT
Added Measurement notes
Added destroy restrictions on Quantity
Replaced BodyTrackingPluginController with Finders concern
Removed 'body_trackers' prefix from paths
Unified styling for textarea

app/controllers/concerns/finders.rb

@@ -0,0 +1,42 @@
+module Concerns::Finders
+  private
+
+  def find_ingredient
+    @ingredient = Ingredient.find(params[:id])
+    @project = @ingredient.project
+  rescue ActiveRecord::RecordNotFound
+    render_404
+  end
+
+  def find_measurement
+    @measurement = Measurement.find(params[:id])
+    @project = @measurement.routine.project
+  rescue ActiveRecord::RecordNotFound
+    render_404
+  end
+
+  def find_measurement_routine
+    @routine = MeasurementRoutine.find(params[:id])
+    @project = @routine.project
+  rescue ActiveRecord::RecordNotFound
+    render_404
+  end
+
+  def find_quantity(id = :id)
+    @quantity = Quantity.find(params[id])
+    @project = @quantity.project
+  rescue ActiveRecord::RecordNotFound
+    render_404
+  end
+
+  def find_quantity_by_quantity_id
+    find_quantity(:quantity_id)
+  end
+
+  def find_unit
+    @unit = Unit.find(params[:id])
+    @project = @unit.project
+  rescue ActiveRecord::RecordNotFound
+    render_404
+  end
+end