AGI: use Common::String::format when possible

Use Common::String::format instead of a MAXPATHLEN-sized char[] buffer.
DRASCULA: use Common::String::format when possible

Use Common::String::format instead of a MAXPATHLEN-sized char[] buffer.
AGI: use shorter sizes for buffers

Instead of allocate them with MAXPATHLEN as size, just give them the
size for the data that are going to be written on them.