Cygwin emacs URL opening fix
The net/browse-url.el provided default for cygwin hosts is broken, it assumes w32-shell-execute works on cygwin, it doesn’t.
The following function is a very simple workaround, cystart will tell windows to open the url, which is most likely the right-ish behaviour (should use default browser)
(defun browse-cygwin (url &optional new-window)
(interactive)
(start-process "browser" nil "cygstart" url))
(setq-default browse-url-browser-function browse-cygwin)
