[performance] Skip unnecessary type checks: arguments to optimised functions should not be wrapped into useless, additional type checks, which cause a massive performance loss. All functions overwriting Function.setArguments handle type checks themselves.

In the concrete example which led to this change, calling ngram:contains took several seconds, which came down to a few milliseconds after the fix.
Merge pull request #273 from wolfgangmm/develop

[performance] Skip unnecessary type checks