[build2] Handling of skipped files

[Boris Kolpackov]

Hi Max,

Sorry for the late reply.

Moldmann Max (DC-MH/ENG52-NA) <Max.Moldmann at boschrexroth-us.com> writes:

> For a better, quicker overview of what the build does - might it be an
> idea to print out all the skips first before the files that get compiled?
> Also maybe you could just summarize e.g. "117 skips" and then list the
> actually compiled files. And only a verbose mode would show the list of
> skipped files. 

Yes, I agree, having all those "skips" interleaved with the actual
compilation commands is not very useful.

I've changed build2 to:

1. Print the skip count in progress.

2. Print a one-line summary of skip count at the end.

Can you give it a try (the staged version) and see how it feels?

Thanks,
Boris