Please push latest upstream version in the tree. Ebuild, copied from sqldeveloper-4.1.3.20.78-r1.ebuild is OK. P.S. Following compatibility issue in bug #582152 we probably should drop 4.0.* versions as obsolete.
4.1.5.21.78 is now in Portage: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=d3c7fa7c6579931a3edea6179e39430fd5ea21df Thanks, Sergey!