Request to add retry() feature to Try::Tiny

Hi Jesse,

I'd like to add a "retry" function to Try::Tiny.

My inspiration came while reworking the error handling in one of my projects.
I kept ending up with the following pattern:

    RETRY:
    try {
        ...
    } catch {
        # check what might have caused the error
        # try to fix what broke
        goto RETRY if $try_again;
    };

Ugly!

This patch makes it possible to simply call retry:

    try {
        ...
    } catch {
        # check what might have caused the error
        # try to fix what broke
        retry if $try_again;
    };

It works much like skip() in Test::More - but doesn't require the user to set up a label and it uses perl's redo function to unwind the stack properly.

I hope you like it!

Steve