Name to all magical unicode/ascii constants in EncodedString and specs

This should help with understanding of these tests and clarify their
intentions. Closes #466.
Merge pull request #484 from rspec/cleanup-encoded-string

Name to all magical unicode/ascii constants in EncodedString and specs
Stop using RSpec::Core::BacktraceFormatter directly.

We want to use the instance of it returned by
RSpec.configuration.backtrace_formatter instead.
Merge pull request #498 from rspec/update-rspec-core-backtrace-formatter-reference

Stop using RSpec::Core::BacktraceFormatter directly.
Ruby 2.1 has deprecated File.exists
Merge pull request #499 from cupakromer/file-exists-deprecated

Ruby 2.1 has deprecated File.exists
Pass a hash to `describe` now that that is properly supported.
Merge pull request #500 from rspec/leverage-subject-fixes

Pass a hash to `describe` now that that is properly supported.
respond_to verifys arity with method_signature_verifier
Merge pull request #501 from rspec/use_method_signature_verifier

Use method_signature_verifier to verify arity in respond_to
use simpler inspect for literals but still detail other objects
Merge pull request #503 from rspec/use_simpler_inspect_for_literals

Use simpler inspect for literals