Updated framework version to match dylib version.

Actually the dylib compatibility version is 3.0.0, but don't break compatibility with previous frameworks, which were compatibility version 1.0.0

Xcode/SDL/SDL.xcodeproj/project.pbxproj

@@ -2773,8 +2773,8 @@
 		00CFA622106A567900758660 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				DYLIB_COMPATIBILITY_VERSION = 1;
-				DYLIB_CURRENT_VERSION = 1;
+				DYLIB_COMPATIBILITY_VERSION = 1.0.0;
+				DYLIB_CURRENT_VERSION = 3.1.0;
 				FRAMEWORK_VERSION = A;
 				HEADER_SEARCH_PATHS = /usr/X11R6/include;
 				INFOPLIST_FILE = "Info-Framework.plist";
@@ -2827,8 +2827,8 @@
 		00CFA628106A568900758660 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				DYLIB_COMPATIBILITY_VERSION = 1;
-				DYLIB_CURRENT_VERSION = 1;
+				DYLIB_COMPATIBILITY_VERSION = 1.0.0;
+				DYLIB_CURRENT_VERSION = 3.1.0;
 				FRAMEWORK_VERSION = A;
 				HEADER_SEARCH_PATHS = /usr/X11R6/include;
 				INFOPLIST_FILE = "Info-Framework.plist";