Don't write all the watched file locations

[alexeagle]

In my build graph, there are hundreds of source files transitively depended on by the target I iblaze

Printing the list of files is spamming my terminal. Also, I'm not sure how this is useful to an end user, if they need to debug what is being watched you could just print an ibazel query ... command that would show them.

Perhaps if you do think it's useful to print the list, it should be a CLI option? (but I think increasing the CLI surface should be done sparingly)