Mash#respond_to? inconsistent with #method_missing

[7even]

After #104 was merged the Hashie::Mash#respond_to? returns false for unknown keys (even with suffixes like _?!) - but #method_missing still can handle this method names.

My suggestion is to revert #104 and try to fix #89 some other way - this is a problem not even directly related to hashie (maybe fix it inside strong_parameters or add something like Hashie::ActiveModel as @jch proposed).

[dblock]

If you have a test for this, that would be helpful.

[7even]

Here's it:

%w(= ? ! _).each do |suffix|
  Hashie::Mash.new(:abc => 'def').should be_respond_to(:"xyz#{suffix}")
end

[dblock]

@7even, take a look at #147. I think this is clearer, but maybe it can be improved? Needs a thorough code review. Thx.