Rewrite the graphing code

This uses more Cocoa classes to draw the lines, making it easier to
understand and hopefully maintain.

Furthermore, we use less memory now, which is nice, but all the
dynamic arrays probably mean more CPU usage.

PBGraphCellInfo.m

@@ -0,0 +1,21 @@
+//
+//  PBGraphCellInfo.m
+//  GitX
+//
+//  Created by Pieter de Bie on 27-08-08.
+//  Copyright 2008 __MyCompanyName__. All rights reserved.
+//
+
+#import "PBGraphCellInfo.h"
+
+
+@implementation PBGraphCellInfo
+@synthesize lines, position, numColumns;
+- (id)initWithPosition: (int) p andLines: (NSArray*) l
+{
+	position = p;
+	lines = l;
+	
+	return self;
+}
+@end