don't draw the resized bitmap if the source and destination are the same
only allocate the return Bitmap when we know we'll need one
Merge pull request #300 from robUx4/dont_resize_same_size

don't draw the resized bitmap if the source and destination are the same
resize bitmaps to a better quality version (with bilinear filtering)
See this thread http://stackoverflow.com/a/7468636

Conflicts:
	ion/src/com/koushikdutta/ion/DefaultTransform.java