Updated method_spec to test additional java_signature return types

Added new specs to validate java_signature returning the correct java form:
  When using primitive arrays as a return type
  When using collections with generics as a return type
Don't push gem from maven?
Remove jruby-jars from pushing as work around by removing it from release since I cannot figure how to turn off the push
Make ClassIndex into an enum, to prevent issues like #1004.
Always log unhandled exceptions in threads.

This is JRuby's fix for https://bugs.ruby-lang.org/issues/6647
which modifies unhandled exception logic in threads to always
log if abort_on_exception != true. This will help avoid the issue
of threads silently disappearing.
Make def return the name as a symbol rather than nil.

This is for 2.1 support, but has no significant impact on earlier
compatibility.
Move exitedException capture above other logic, to ensure it sets.
do not push jruby-jars gem via maven [skip ci]
trick maven to attach javadocs [skip ci]
do not push jruby-jars gem via maven [skip ci]
trick maven to attach javadocs [skip ci]
Bump for release of readline
Bump for release of readline
IT HAS BEGUN!

Remove 1.8 tests and stdlib and start migrating boot logic toward
a single runtime compatibility mode.
Eliminate calls to Ruby.is1_8 and is1_9.
Oopsed one line that should not be there for 1.9+.
Remove some remaining version-switching nuggets.
Revert "Move exitedException capture above other logic, to ensure it sets."

This reverts commit be4d7212a1bc7e5d516d7d1d6f757d3b34d8d8cd.
Revert "Always log unhandled exceptions in threads."

This reverts commit 79423216e3aa3ed0dc377aa1998471be02845613.
Remove --<version> flag from mspec runs.