Updated My5Heap class and resolve #4
updated deleteMax
Remove AA/src/MyHeap1.java
Removed accidentaly added file.
Update My5Heap
Change refernece of `size` to `next` in `deleteMax()`.
Replace redundant code with swap().
Update My5Heap
Fix the bug that deleteMax does not alway returns the highest priority.
Refactor to reduce redundant code.
Update My5Heap
Rename per_Down() method to percolateDown() to fit Java convention.
Refactor code in percolateDown() to remove redundancy.
Update My5Heap
Refactor deleteMax() to remove redundant codes.
Extract codes in percolateDown() to maxChildrenOf() to increase
readability.
Merge pull request #6 from AlgoCon/DeleteMax

Updated My5Heap class and resolve #4