ImageSpan alignment (i.e., BASELINE over BOTTOM)

[tomrenn]

I made a tiny fork of this library because my span was not properly aligned. A default ImageSpan uses DynamicDrawableSpan.ALIGN_BOTTOM with no configuration to have the AwesomeTextHandler to use ALIGN_BASELINE.

It's a rather tiny change, but I'd like to know if there's interest to add that to this library before I make a PR.

[janakagamini]

If this makes the "awesomefied" text properly align with the rest of the text in a line (regardless of the size/shape of the background, yes I'm interested.