Fixing issues with determining a textbox string bounds.

Currently the GetStringBounds returns a rect which is not correct.
Drawing the textbox with the rect provided doesn't create a textbox
with the text laid out as expected.  Fixing some bugs in the build
layout of text box designer and an issue with MOAIGlyph::GetRect which
was causing these problems.

See the before and after pictures:
![before](https://f.cloud.github.com/assets/3893074/678903/d2ebca06-d949-11e2-8407-059c4e45e78e.png)
![after](https://f.cloud.github.com/assets/3893074/678902/d2e203f4-d949-11e2-8889-48bbfae2d12b.png)