[4.0] adds batched output for logging

Created by: stringparser

Coming from #691. Similar changes:

• adds lib/batchThese.js
• modifies lib/log/events.js logging for start and stop events.

One difference with the another PR is that one can adjust how many items the batch can have based on the name argument. That is because the start event for example fires more often than other events. If you "push" it to wait for the next batch you can end up with something like this:

# js:pipeline -> gulp.series('jsx', 'js');
# css:pipeline -> gulp.series('css');
# default -> gulp.parallel('js:pipeline', 'css:pipeline');
[17:10:37] Starting 'default', 'js:pipeline', 'css:pipeline', 'jsx'
[17:10:37] Finished 'css:pipeline' after 1.09 ms, 'jsx' after 1.06 ms, 
[17:10:37] 'js' after 63 μs
[17:10:37] Starting 'js'
[17:10:37] Finished 'js:pipeline' after 2.21 ms, 'default' after 3.24 ms

instead of this

# added minify to the js:pipeline to se if it worked
[17:22:57] Starting 'default', 'js:pipeline', 'css:pipeline', 'jsx', 'js', 'minify'
[17:22:57] Finished 'css:pipeline' after 798 μs, 'jsx' after 765 μs, 
[17:22:57] 'js' after 56 μs, 'minify' after 409 μs
[17:22:57] Finished 'js:pipeline' after 2.33 ms, 'default' after 3.44 ms

thus wishing to have batches with different length.

The gulpfile is on this gist