Trial by Zed Lopez

This is just asimple way to facilitate testing code that isn't command-centric, intended for use with regtest (but potentially useful without it). Just set up tests by name like so:

``` Trial "one and one": let i be 1; let x be i + 1; say "[x][line break]"; ```

and a corresponding regtest entry:

``` > try one and one /^2$ ```