SDL_ttf SizeText API for wrapped text (patch linked)

Hi,

I have added a function to SDL_ttf for my own programs to find measure the
size of a box required to enclose text rendered when using
TTF_RenderUTF8_Blended_Wrapped without actually rendering it. I believe
this may be useful to other people so I have linked the diff required to be
applied that will provide this functionality.

In addition, due to this change I have changed the behavior of
TTF_RenderUTF8_Blended_Wrapped to returning a surface whose width is
exactly the width of the longest line in the wrapped text.

The previous behavior simply returned a surface with a width of the text
unwrapped but a height large enough to accommodate the number of lines
resulting from wrapping. This was extremely inefficient since long text
would cause needlessly large textures.

I have attempted to emulate the coding convention used in SDL_ttf as
closely as possible. If there are violations I am willing to learn of them.

The changes related are available for public scrutiny here:

David Siaw