Load helpers at View construction.

Loading helpers earlier in View's lifecycle allows for the removal of many duplicated code segments and a now useless property. It slightly modifies how View behaves in a test case, but that issue is easily remedied by calling loadHelpers() a second time.

This primarily fixes issues where helpers may not be loaded in View subclasses if they override any of View's methods. This is particularly problematic when aliased helpers are involved.

Related to #1564