dev-java/jflex: Rewrite for version bump to 1.6.1

dev-java/jflex: Rewrite for version bump to 1.6.1

Rewritten using java-pkg-simple to give us more control over this
tricky package. javacup has become a PDEPEND, meaning that the bundled
version is automatically used on the first build instead of it having
a system-jflex USE flag.

~arm keyword added with workarounds for different problems encountered
with both IcedTea and Oracle.

~ppc64 keyword temporarily dropped until it gets Java 7, which the
newer javacup requires.

Please stabilise this at the same time as dev-java/qdox-1.12.1-r1.

Package-Manager: portage-2.2.20.1