Added branching functionality
Merge branch 'feature/undo/bootstrap' of github.com:Derkje-J/programming-life into feature/undo/bootstrap

Conflicts:
	app/assets/javascripts/models/tree.js.coffee
	app/assets/javascripts/models/undotree.js.coffee
	app/assets/javascripts/views/undo.js.coffee
Merge branch 'feature/undo/bootstrap' into develop