Add basic spec for opening a FIFO.
A few basic trace_var specs.
Add spec for Method#to_proc producing a proc that receives blocks.

This appears to be a 1.8.7 bug, since it does not pass the block
along. I've filed #5926 and guarded it with ruby_bug.
Add basic specs for String#% %<foo> form.
Add spec for args passed to module/class_exec.
Add spec to confirm methods that match operators call.
Add spec for Socket#accept_nonblock exceptions.
Hash#default_proc: Tweak version
Hash#default_proc=: Spec change for Ruby 2.0 [redmine:4234]
Chunked size may differ between the implementations.

At least 1.8.7 and 2.0.0 (r35281) differ.
Add @socket.io as mock for 2.0.
Wait the detaching thread with join.

* the forked process should exit without killing.
* must wait the detaching thread before evaluating lambda.
  For this purpose, Thread#join is suitable.
Clean up ProcessSpecs::Daemonizer.
Move Module#freeze specs

These are actually testing `def` for a singleton class.
Add specs for rb_id2str
Fix comparison check in specs
Add spec for exec'ing a string with \00
Specs for Ruby 1.9 Hash#fetch to raise KeyError when no key is found
Cleaning up whitespace
Add specs for sprintf reference by name