Make matchit's "%" ignore Range.end method

With the following code, matchit's "%" key will now jump between line 1
and line 3, as it should:

```ruby
if x
  (1..5).end
end
```

Ruby allows methods with keyword names, such as "end".  That was confusing Vim's "%" command (go to match), since the `end` in `(1..5).end` looks like a keyword.

The fix is similar to what is done farther down in `syntax/ruby.vim`, in the section that defines `rubyKeywordAsMethod`: If "end" is preceded by "." or "::", then it is a method name.