Re-work installed vs uninstalled state

These two API's now prefer to use activate/deactivate if available over our older custom install algorithm.

@@ -288,24 +288,11 @@ static char kInstalledConstraintsKey;
 #pragma mark - MASConstraint
 
 - (void)activate {
-    if ([self supportsActiveProperty] && self.layoutConstraint) {
-        if (self.hasBeenInstalled) {
-            return;
-        }
-        self.layoutConstraint.active = YES;
-        [self.firstViewAttribute.view.mas_installedConstraints addObject:self];
-    } else {
-        [self install];
-    }
+    [self installedView];
 }
 
 - (void)deactivate {
-    if ([self supportsActiveProperty]) {
-        self.layoutConstraint.active = NO;
-        [self.firstViewAttribute.view.mas_installedConstraints removeObject:self];
-    } else {
-        [self uninstall];
-    }
+    [self uninstall];
 }
 
 - (void)install {
@@ -313,6 +300,12 @@ static char kInstalledConstraintsKey;
         return;
     }
     
+    if ([self supportsActiveProperty] && self.layoutConstraint) {
+        self.layoutConstraint.active = YES;
+        [self.firstViewAttribute.view.mas_installedConstraints addObject:self];
+        return;
+    }
+    
     MAS_VIEW *firstLayoutItem = self.firstViewAttribute.item;
     NSLayoutAttribute firstLayoutAttribute = self.firstViewAttribute.layoutAttribute;
     MAS_VIEW *secondLayoutItem = self.secondViewAttribute.item;
@@ -387,6 +380,12 @@ static char kInstalledConstraintsKey;
 }
 
 - (void)uninstall {
+    if ([self supportsActiveProperty]) {
+        self.layoutConstraint.active = NO;
+        [self.firstViewAttribute.view.mas_installedConstraints removeObject:self];
+        return;
+    }
+    
     [self.installedView removeConstraint:self.layoutConstraint];
     self.layoutConstraint = nil;
     self.installedView = nil;