RubyCocoa SVN

Raise ArgumentError by `NSArray#[range]=nil` on ruby-2.x

# ruby-1.8 deletes elements when the given value is nil
ary = [1, 2, 3, 4, 5]
ary[1..2] = nil
ary # => [1, 4, 5]

# ruby-2.1 sets nil
ary = [1, 2, 3, 4, 5]
ary[1..2] = nil
ary # => [1, nil, 4, 5]
# NSArray cannot contain nil value.
nsary = OSX::NSArray.arrayWithArray([1, 2, 3, 4, 5])
nsary[1..2] = nil # => ArgumentError

Fix wrong assertion in test_upto

Compare RUBY_VERSION as string not by #to_f

- before: RUBY_VERSION.to_f >= 2.0
- after: RUBY_VERSION >= '2.0'

Fix OSX::NSString#slice!(num) not delete by given position on ruby-2.x.

Fix test_upto fails on ruby-2.x

Range#each yields String when its element responds to :to_str
on ruby-2.0 or later.
see range_each() in range.c of ruby source code.

str1 = OSX::NSString.stringWithString('A')
str2 = OSX::NSString.stringWithString('Z')
(str1..str2).each do |s|
# `s' is OSX::NSString on ruby-1.8
# `s' becomes String on ruby-2.0 or later
:
end

Add encoding conversion between Ruby and NSString for ruby-2.x [WIP]

Use $KCODE only for ruby-1.8

delete unwanted

Fix test_include fails on ruby-2.x

Fix test_ref_nth fails on ruby-2.x