Drop Ant build

[paulvi]

As mentioned in https://github.com/nextinterfaces/http4e/pull/5#issuecomment-343346845

ant build should be possibly dropped. (Once maven/tycho is perfect, and it make too hard to support both)

With that eclipse.sdk folder should go away too, as it make git repository very heavy.
Git repository maybe will need to be purged or somehow other way change, so that old binaries don't stay in history.