WIP: display "use capacity" checkbox
WIP: Save use_capacity
making burndown use capacity
fixing singleton count
WIP: save use_capacity in db and display its value
Merge branch '2217_ideal_burndown_line_with_capacity_field' of tuleap.net:tuleap/tuleap/dev into 2217_ideal_burndown_line_with_capacity_field

* '2217_ideal_burndown_line_with_capacity_field' of tuleap.net:tuleap/tuleap/dev:
  fixing singleton count
  making burndown use capacity
Add upgrade script
fixing bugs
re-ordering field methods- using correct one in views
Better naming & remove singleton
Do not rely anymore on User for the capacity field
Some refactoring

remove caching of capacity
implements doesBurndownUseCapacityField
Readable
Merge branch '2217_ideal_burndown_line_with_capacity_field' of tuleap.net:tuleap/tuleap/dev into 2217_ideal_burndown_line_with_capacity_field

* '2217_ideal_burndown_line_with_capacity_field' of tuleap.net:tuleap/tuleap/dev:
  Some refactoring
  Do not rely anymore on User for the capacity field
  Better naming & remove singleton
  re-ordering field methods- using correct one in views
  fixing bugs

Conflicts:
	plugins/tracker/include/Tracker/FormElement/Tracker_FormElement_Field_Burndown.class.php
	plugins/tracker/include/Tracker/FormElement/View/Admin/Field/Burndown.class.php
Clean-up
Remove useless condition
reverting file
Merge branch '2217_ideal_burndown_line_with_capacity_field' of tuleap.net:tuleap/tuleap/dev into 2217_ideal_burndown_line_with_capacity_field

* '2217_ideal_burndown_line_with_capacity_field' of tuleap.net:tuleap/tuleap/dev:
  reverting file
ng burndow ignore capacity if value is zero
adding burndown view test