Activate Eshell and Magit outside of project for helm-projectile

Currently both `helm-projectile-switch-to-eshell` and `helm-projectile-vc` use projectile-project-root to get full pathnames, but `projectile-project-root` does not allow usage outside of a project. `projectile-project-root` is not really necessary since the project directories already are relative to home directory.