[Heroes.rtf] New donor!
[make-dmg] Fix code signing being stripped by using `hdiutil create` instead of `hdiutil makehybrid`.

This was Apple's suggestion in bug 18524296 and it appears to work (it must
do -hfs-openfolder automatically, though it is not mentioned anywhere in the
docs).
[make-dmg] Just go right to the UDBZ formatted .dmg (at the cost of about 1% larger .dmg)
[make-dmg] More more more stupid workarounds [Strange work around for -5341 error on Mavericks]

References:
  https://stackoverflow.com/questions/18621467/error-creating-disk-image-using-hdutil
  https://discussions.apple.com/thread/4712306