Fix ArgMatcher consuming extra arguments when max_values is set

[sphynx]

Closes #1480

[sphynx]

I had to change error type in one of doc-string tests from TooManyArguments to UnknownArgument. I believe that it's more consistent this way, because now if we pass 2 arguments when max_values = 1(i.e. one more than needed) - we get TooManyArguments, but if we pass 3 arguments to the same option -- we already get UnknownArgument for the third one (while it's conceptually still TooManyArguments). I demonstrated this situation in two extra tests, included in this PR.

I believe that it's a good idea to guide the process of matching arguments by the information from max_values and min_values.

[kbknapp]

@sphynx Sorry for the delay and thank you for the PR. If you're still interested in this PR could you please rebase on the latest master (which now contains the v3-beta code)? It looks like the third test works natively on v3, but test 1 and 2 still fail (2 with TooManyValues instead of the correct UnknownArgument and 1 due to MissingRequired instead of the correct UnkownArgument)