Update a String#{to_sym,intern} spec for "+,-"

Follow ticket-9048
See below links

* http://bugs.ruby-lang.org/issues/9048
* https://github.com/ruby/ruby/pull/383#issuecomment-26915103
Improve some special operators specs
Remove outdated special operators
Add rb_class_real per #2358
debian stable package support for rubinis-2.2.

File necessary to build a .deb package for Debian Stable(wheezy).

Rubinius 2.2.6+ or MRI 1.8/1.9 can be used to build the package. There were
changes in Rubinius prior to 2.2.4 to make this work.

Conflict & Replace MRI ruby packages.

gem is a separate alternatives command in rubygems1.8. This is broken. The gem
command is include in ruby1.9.1 package and in rubinius it is also included.
The gem command must switch in lock step with the ruby command otherwise
everything breaks.

I force package conflict until the MRI packages are fixed.

dpkg-buildflags is used for the default build flags. This fixes some common
problems and allows system specific configuration.

Description in control file by @brixen
"Rewrote the description as one paragraph to meet the formatting restrictions.
I focused on more direct technical language as I expect the audience for the
description to be knowledgable about Ruby, programming, or the technology
described generally."
Updated CI specs to RubySpec 61a1ea88.
Fixed Bignum#bit_length spec describe text.
Updated CI tags.
Fixed missed ruby_version_is guard.
Like said in https://github.com/rubinius/rubinius/pull/2998#discussion_r11291381 use parentheses for arguments in defs
Merge pull request #3004 from Benny1992/master

Like said in https://github.com/rubinius/rubinius/pull/2998#discussion_r...
Grab string length before copying strings

This fixes a valgrind warning on newer Linux version. It's not really a
bug, but it's an easy enough workaround to fix warnings in valgrind
because of strlen() usage.
Updated CI specs to RubySpec cdb70125.
Fixed Hash#reject for 2.1 behavior.
Updated CI tags.
Revert "Fixed Hash#reject for 2.1 behavior."

This reverts commit 4b547a15733b3f79128f8993168b5ea5e1306017.

See
https://www.ruby-lang.org/en/news/2014/03/10/regression-of-hash-reject-in-ruby-2-1-1/

Thanks @dbussink.
Updated CI specs to RubySpec 12438aff.
Updated CI tags for Proc#source_location.

Compare the output of MRI and Rubinius for the following script:

$ cat -n proc.rb
     1  class A
     2    def hello
     3      __method__
     4    end
     5
     6    def bye
     7      method(__method__).to_proc
     8    end
     9  end
    10
    11  p A.new.hello
    12
    13  m = A.new.method(:hello)
    14  p m
    15  p m.source_location
    16
    17  prc = m.to_proc
    18  p prc
    19  p prc.source_location
    20
    21  m = A.new.method(:bye)
    22  p m
    23  p m.source_location
    24
    25  prc = A.new.bye
    26  p prc
    27  p prc.source_location

  ruby 2.1.0p0 (2013-12-25 revision 44422) [x86_64-darwin13.0]
  :hello
  #<Method: A#hello>
  ["proc.rb", 2]
  #<Proc:0x007f804c0fa338 (lambda)>
  ["proc.rb", 2]
  #<Method: A#bye>
  ["proc.rb", 6]
  #<Proc:0x007f804c0f9ed8 (lambda)>
  ["proc.rb", 6]

  rubinius 2.2.6.n78 (2.1.0 ac8f0e2f 2014-03-19 JI) [x86_64-darwin13.1.0]
  :hello
  #<Method: A#hello (defined in A at /source/rubyspec/rubyspec/proc.rb:2)>
  ["/source/rubyspec/rubyspec/proc.rb", 2]
  #<Proc:0x170@/source/rubyspec/rubyspec/proc.rb:3 (lambda)>
  ["/source/rubyspec/rubyspec/proc.rb", 3]
  #<Method: A#bye (defined in A at /source/rubyspec/rubyspec/proc.rb:6)>
  ["/source/rubyspec/rubyspec/proc.rb", 6]
  #<Proc:0x18c@/source/rubyspec/rubyspec/proc.rb:7 (lambda)>
  ["/source/rubyspec/rubyspec/proc.rb", 7]
Removed Precision module.
Updated CI specs to RubySpec ae7f25f8.