Fix pie crash #78 #96 #80 #45

@@ -123,7 +123,7 @@
     
 	_currentTotal += currentDataItem.value;
 	
-    NSString *titleText = currentDataItem.description;
+    NSString *titleText = currentDataItem.textDescription;
     if(!titleText){
         titleText = [NSString stringWithFormat:@"%.0f%%",currentDataItem.value/ _total * 100];
     }

@@ -17,8 +17,8 @@
                             color:(UIColor*)color
                       description:(NSString *)description;
 
-@property (nonatomic, readonly) CGFloat   value;
-@property (nonatomic, readonly) UIColor  *color;
-@property (nonatomic, readonly) NSString *description;
+@property (nonatomic) CGFloat   value;
+@property (nonatomic) UIColor  *color;
+@property (nonatomic) NSString *textDescription;
 
 @end

@@ -8,14 +8,6 @@
 
 #import "PNPieChartDataItem.h"
 
-@interface PNPieChartDataItem()
-
-@property (nonatomic, readwrite) CGFloat   value;
-@property (nonatomic, readwrite) UIColor  *color;
-@property (nonatomic, readwrite) NSString *description;
-
-@end
-
 @implementation PNPieChartDataItem
 
 
@@ -31,7 +23,7 @@
                             color:(UIColor*)color
                        description:(NSString *)description{
 	PNPieChartDataItem *item = [PNPieChartDataItem dataItemWithValue:value color:color];
-	item.description = description;
+	item.textDescription = description;
 	return item;
 }