Implemented iteration on Enumerable

[matteofabbri]

As disqussed on CodeProject i added the foreach as a runtime function.
It can be used in both ways: with pipe and not.

[1,2,3,4] | each(console.writeln) // prints 1\n2\n3\n4\n
each([1,2,3,4], console.writeln) // prints 1\n2\n3\n4\n

💃

now adding Linq style functions like select, where and so on.

[FlorianRappl]

Can you please re-submit to devel? master only contains the latest release, not the current working snapshot. (Unfortunately, on GitHub one cannot just move the PR - the submitter has to re-submit the PR.)

Also I don't know why the diff looks so strange; it basically removed everything and re-added everything. This is therefore quite hard to read / digest. Is there a way to have the usual diff?

Final thing (I really want to accept this PR, but this is something that really needs to be done): Even though there is no concrete style guide I strictly followed the rule of always using statement blocks instead of single statements (e.g., for if, for, and while construct; I've seen that they are now dropped partially (e.g., in ParseKeywordStatement) - could you please restore them?

Thanks a lot for your effort - much appreciated 👍