- Fix AABB size with left or right text alignment

left or right text alignment should only pad the width, previously both width and height were being doubled.
Merge pull request #88 from capnlove/ExplicitCell_GetWidth

Added ImageAsset.getExplicitCellWidth and ImageAsset.getExplicitCellHeight
Merge pull request #97 from lilligreen/fix/ImageFontSize

Fix ImageFont AABB size with left or right text alignment