Replace $curl-lock-data constants with enums

[fraya]

dylan-curl/src/lib-curl/easy/lib-curl-easy-share.dylan

Lines 30 to 35 in d0554d3

	// $curl-lock-data-none = 0;
	define constant $curl-lock-data-share = 1; // undocumented
	define constant $curl-lock-data-cookie = 2;
	define constant $curl-lock-data-dns = 3;
	define constant $curl-lock-data-ssl-session = 4;
	define constant $curl-lock-data-connect = 5;