Cleaned up setter methods

Added shadow color property from mutualmobile#294

MMDrawerController/MMDrawerController.h

@@ -221,6 +221,13 @@ typedef void (^MMDrawerControllerDrawerVisualStateBlock)(MMDrawerController * dr
  */
 @property (nonatomic, assign) CGSize shadowOffset;
 
+/**
+ The color of the shadow drawn off of 'centerViewController` when a drawer is open.
+ 
+ By default, this is set to the systme default (opaque black).
+ */
+@property (nonatomic, strong) UIColor * shadowColor;
+
 /**
  The flag determining if a custom background view should appear beneath the status bar, forcing the child content to be drawn lower than the status bar. This property is only available for > iOS 7.0 to take into account for the new behavior of the status bar.
  

MMDrawerController/MMDrawerController.m

@@ -193,15 +193,16 @@ -(void)commonSetup{
     [self setCenterHiddenInteractionMode:MMDrawerOpenCenterInteractionModeNavigationBarOnly];
 
     // set shadow related default values
-    self.shadowOpacity = MMDrawerDefaultShadowOpacity;
-    self.shadowRadius = MMDrawerDefaultShadowRadius;
-    self.shadowOffset = CGSizeMake(0, -3);
+    [self setShadowOpacity:MMDrawerDefaultShadowOpacity];
+    [self setShadowRadius:MMDrawerDefaultShadowRadius];
+    [self setShadowOffset:CGSizeMake(0, -3)];
+    [self setShadowColor:[UIColor blackColor]];
 
     // set default bezel range for panGestureReconizer
-    self.bezelPanningCenterViewRange = MMDrawerBezelRange;
+    [self setBezelPanningCenterViewRange:MMDrawerBezelRange];
 
     // set defualt panVelocityXAnimationThreshold
-    self.panVelocityXAnimationThreshold = MMDrawerPanVelocityXAnimationThreshold;
+    [self setPanVelocityXAnimationThreshold:MMDrawerPanVelocityXAnimationThreshold];
 }
 
 #pragma mark - State Restoration
@@ -885,6 +886,11 @@ - (void)setShadowOffset:(CGSize)shadowOffset{
     [self updateShadowForCenterView];
 }
 
+- (void)setShadowColor:(UIColor *)shadowColor{
+    _shadowColor = shadowColor;
+    [self updateShadowForCenterView];
+}
+
 -(void)setOpenSide:(MMDrawerSide)openSide{
     if(_openSide != openSide){
         _openSide = openSide;
@@ -1280,6 +1286,7 @@ -(void)updateShadowForCenterView{
         centerView.layer.shadowRadius = self.shadowRadius;
         centerView.layer.shadowOpacity = self.shadowOpacity;
         centerView.layer.shadowOffset = self.shadowOffset;
+        centerView.layer.shadowColor = [self.shadowColor CGColor];
 
         /** In the event this gets called a lot, we won't update the shadowPath
         unless it needs to be updated (like during rotation) */