Modest tweaks to IjFolder

Summary:
1) .equals() now compares hashCode() first
2) .hashCode() uses xor, not or

Test Plan: `buck test //test/com/facebook/buck/ide/intellij/projectview && buck test //test/com/facebook/buck/ide/intellij`

Reviewed By: styurin

fbshipit-source-id: a4039ea

src/com/facebook/buck/ide/intellij/model/folders/IjFolder.java

@@ -115,16 +115,17 @@ public boolean equals(Object other) {
     }
 
     IjFolder otherFolder = (IjFolder) other;
-    return getPath().equals(otherFolder.getPath())
+    return (hashCode() == otherFolder.hashCode())
+        && getPath().equals(otherFolder.getPath())
         && (getWantsPackagePrefix() == otherFolder.getWantsPackagePrefix())
         && getInputs().equals(otherFolder.getInputs());
   }
 
   @Override
   public int hashCode() {
     return (getPath().hashCode() << 31)
-        | (getWantsPackagePrefix() ? 0x8000 : 0)
-        | inputs.hashCode();
+        ^ (getWantsPackagePrefix() ? 0x8000 : 0)
+        ^ inputs.hashCode();
   }
 
   @Override