can't create a compra with proveedor consumidor final
upgrade ember

ember: 1.4.1-beta.1
ember-data: 1.0.0-beta.7.f87cba88
highlighting cliente/proveedor with text-danger when it has error
bugfix: this button was triggered when form submitted
new ember-data of persisting associations
set tipoId picker when not finding cliente/proveedor. This fixes #12
using pry
removed support for item.base
bugfix
added Bandango.numberForCurrencyHelper
refactored ItemBaseMixin
not allowing to destroy clientes that have compras/ventas