Add spec for lookup scope for autoload
Revert "Specify correct version guards"

This reverts commit dc5ef4f63c7360aa339d2e31b6607f2ceebc665f.
Autoload const removing behavior is the same on 1.8 and 1.9
Sleep for 0.1 seconds is long enough
Add spec for resolving autoload constant from metaclass scope
Correctly spec rb_str_new_cstr as 1.9-only CAPI

Currently, rb_str_new_cstr is spec'ed as a function available under both 1.8
CAPI and 1.9 CAPI in spec/ruby/optional/capi/ext/rubyspec.h. This is not true.
As a version guard is correctly used in spec/ruby/optional/capi/string_spec.rb,
it is only declared under 1.9 CAPI, not under 1.8 CAPI.

In 1.8 mode, rb_str_new_cstr specs are only compiled, not run, thanks to the
version guard. So, there is no spec failures. However, this commit suppresses
the following warning from clang:

  spec/ruby/optional/capi/ext/string_spec.c:165:12: warning:
    implicit declaration of function 'rb_str_new_cstr' is invalid in C99
      [-Wimplicit-function-declaration]
      return rb_str_new_cstr(NULL);
             ^
  1 warning generated.

Also, #undefs aren't needed in spec/ruby/optional/capi/ext/mri.h, because
rb_str_new_cstr is now correctly declared only in 1.9 CAPI.
Added new rubyspec for require_relative in eval environment
Fix typo: wihtout => without
Added C-API specs for rb_file_open_str.
Added C-API specs for FilePathValue.
Added C-API specs for rb_str_inspect.
C-API spec for rb_str_subseq.
Spec for rb_io_addstr return value.
More specs for rb_scan_args with 1.9 features.
Add a spec for undefined behavior in Fixnum#**
Add specs for singleton_method_(added|removed|undefined)
Add specs for Module#method_defined and Module#method_removed to be private methods
Add specs for String#% with single length strings in 1.9 mode
Correctly update args array size after 267d050
Fix specs for situations where getaddrinfo returns '' and not '0.0.0.0'