Grid dropdowns added to reports.
	modified:   Gemfile
	modified:   app/controllers/surveyor_gui/reports_controller.rb
	modified:   app/views/surveyor_gui/reports/_graphs.html.haml
	modified:   app/views/surveyor_gui/reports/_grid_dropdown.html.haml
	modified:   app/views/surveyor_gui/reports/_show_report.html.haml
	modified:   lib/surveyor_gui/models/column_methods.rb