Crawl Directives compile error messages are awful

[tokahuke]

The current compiler now

1. Just shows the first error it finds.
2. Has only the nom default error messages to fall back to to. And those messages are all but intuitive. Even I have a hard time getting the problem in .lcd code and I designed the syntax!

We need more insightful error messages.

[tokahuke]

On v0.4.0, it at least points to the line and column of the error (and there is a bit of ANSI term fluff thrown into).