Unbind the search controller before switching views

Otherwise, the app will run fine in Debug mode but not when you
run it otherwise :|

PBCLIProxy.mm

@@ -31,6 +31,7 @@
 	// FIXME I found that creating this redundant NSURL reference was necessary to
 	// work around an apparent bug with GC and Distributed Objects
 	// I am not familiar with GC though, so perhaps I was doing something wrong.
+
 	NSURL* url = [NSURL fileURLWithPath:[repositoryPath path]];
 	NSArray* arguments = [NSArray arrayWithArray:args];
 	PBGitRevSpecifier* rev = [[PBGitRevSpecifier alloc] initWithParameters:arguments];

PBGitWindowController.m

@@ -40,7 +40,8 @@
 - (void)changeViewController:(NSInteger)whichViewTag
 {
 	[self willChangeValueForKey:@"viewController"];
-	
+	self.searchController = nil;
+	[self unbind:@"searchController"];
 	if ([viewController view] != nil)
 		[[viewController view] removeFromSuperview];	// remove the current view
 	
@@ -60,8 +61,9 @@
 	
 	// Allow the viewcontroller to catch actions
 	[self setNextResponder: viewController];
-	[self bind:@"searchController" toObject:viewController withKeyPath:@"commitController" options:nil];
-	
+	if ([viewController respondsToSelector:@selector(commitController)])
+		[self bind:@"searchController" toObject:viewController withKeyPath:@"commitController" options:nil];
+
 	// make sure we automatically resize the controller's view to the current window size
 	[[viewController view] setFrame: [contentView bounds]];