customizable ghost explosion contents

[ncrecc]

reposting from the 4.4.0.0 pre-release 4 thread for better visibility:

this would break away from GDash, but it would be cool if eventually we could customize what elements can emerge from ghost explosions (like what happened with the gray ball in Mirror Magic). here's a mockup based on the default elements ghost explosions produce:

ghost_custom.png (16.81 KiB) Viewed 153 times

(the "choice type" options are the same as for the gray ball in MM)