Hello, this patch add a user option for specify in which major modes
should global-hl-line-mode be switched on.

Originally i wanted to replace global-hl-line define-minor-mode
definition with define-globalized-minor-mode, however i found that this
was already done and was reverted in
*a34afbf2aea2fdaf691f4bf250a18991b21301d7* commit, so I decided to bring
this feature, since i find this better than using add-hook.