File#flock: ensure that flock blocks

this tests fails currently under JRuby 1.7.0, so it might be nice to have.
Add spec around calling Symbol#to_proc for a method that yields
File.open on a FIFO blocks the interpeter on 1.8.7

On 1.9.3 you can run `Thread.new { File.open('some_fifo', 'w') }` and
the interpreter will return the thread object as expected, however on
1.8.7 (and, by extension ree) we discover that `Thread.new` never
returns.

I'm not exactly sure the best way to deal with this, so if there is a
better way that just bypassing this spec on 1.8 then please let me know.
Fixed multi-byte symbol spec.
Fixed Proc#arity specs.
Revert "use Thread.pass in looping threads to ensure others get a chance to run"

This reverts commit c102e7fe73c0fdf47628410df03af4751bc8a57b.
Fixed Thread[.#]abort_on_exception specs.
Remove race from TCPSocket.new specs.

The SpecTCPServer does not echo when receiving QUIT so the read
would block, randomly, of course.
Some SocketSpecs::SpecTCPServer cleanups.
Restore Thread.abort_on_exception state.
Revert "Update specs for Refinements conforming to the latest spec described at <https://bugs.ruby-lang.org/projects/ruby-trunk/wiki/RefinementsSpec>."

This reverts commit 45fe77547a063284cbc04faf6708a426ed68f712.
Revert "MRI r37619 remove Kernel#using, and add main.using instead"

This reverts commit 51ecb834238a162081c57c03bbca4718d37a5963.
Revert "Add missing string_refinement.rb file."

This reverts commit ad6a980d7ad4b5c2d10df64933180089f493e3c9.
Revert "Add additional examples from a_matsuda's talk."

This reverts commit d9bd1363d29d73ee32c06ee73dd0afb2f3ddaf05.
Revert "using is defined on Kernel, not Module."

This reverts commit ee0539fbf8381e9dfc1ec2290d91f7d7d161d665.
Revert "Initial refinement specs; not pretty, but it's a start."

This reverts commit f603267b0afb2d9760d5a480078ee8cbb8a0984d.
Raised issue #7908 on bugs.ruby-lang.org.
Merge pull request #177 from jamesotron/file-open-fifo-fails-on-187

File.open on a FIFO blocks the interpeter on 1.8.7
Added notification email and limit JDKs tested. [ci skip]
Disable ruby_bug guard.