[controller] load departments and allow params for department_id in specialties
[model] add department associations
[spec/model] department associations
[views] add department fields
[migrate] add deparment association to specilaties
[spec/request] test deparment selection in specialties
Merge branch 'master' of github.com:Genshin/GAKUEngine

Conflicts:
	core/app/models/gaku/department.rb
	core/spec/models/department_spec.rb