makefont function that return bytes instead of writing to files.

[botchedpotato]

Currently if you design your program in such a way that you allow the user to specify a font, then you have to use the makefont function to convert fonts first and this writes to the disk and this could cause problems. It would be cool if there was a variant of the makefont function that return the bytes it would write to the file, especially considering that there is a AddUft8bytes function.