Add a preferences window

This adds a preference window with default preferences to change the
sparkle options and to set a custom path to a git binary.

ApplicationController.m

@@ -13,6 +13,8 @@
 #import "PBCLIProxy.h"
 #import "PBServicesController.h"
 #import "PBGitXProtocol.h"
+#import "PBPrefsWindowController.h"
+#import "PBNSURLPathUserDefaultsTransfomer.h"
 
 @implementation ApplicationController
 @synthesize cliProxy;
@@ -30,6 +32,10 @@
 		self.cliProxy = [PBCLIProxy new];
 	}
 
+	/* Value Transformers */
+	NSValueTransformer *transformer = [[PBNSURLPathUserDefaultsTransfomer alloc] init];
+	[NSValueTransformer setValueTransformer:transformer forName:@"PBNSURLPathUserDefaultsTransfomer"];
+	
 	return self;
 }
 
@@ -78,6 +84,11 @@
 	[firstResponder terminate: sender];
 }
 
+- (IBAction)openPreferencesWindow:(id)sender
+{
+	[[PBPrefsWindowController sharedPrefsWindowController] showWindow:nil];
+}
+
 - (IBAction)installCliTool:(id)sender;
 {
 	BOOL success               = NO;