dev-java/boot-bin: Added at 2.6.0

dev-java/boot-bin: Added at 2.6.0

This is mostly just giving users a better choice than "sudo bash curl..."

boot will still have to install its own dependencies when executed via maven
glue into ~/.m2/, but this still means they can easily get `boot` accessible
globally in "$PATH" without security paranoia, and from then on it
"mostly just works" without needing to understand boot-specific install
procedures.

Ideally this itself will be built from sources one day, but java upstream
logic fights this at every stage.

Also, "boot -u" still does "something", but it doesn't do anything useful.

Package-Manager: portage-2.3.0