[Fixes #137] Improve reporting

[marcandre]

Before:

1 useless nonterminals
2 useless rules
1 shift/reduce conflicts

After:

1 useless nonterminals:
  dummy
2 useless rules:
  #4 (dummy)
  #5 (dummy)
1 shift/reduce conflicts
Turn on logging with "-v" and check ".output" file for details

Detailed list are limited to 10

[duerst]

Very minor comment: If the .output file is similar to the one bison produces, then I wouldn't call this a log file.

[marcandre]

Very minor comment: If the .output file is similar to the one bison produces, then I wouldn't call this a log file.

I agree it's not what I would expect of a "log file", but it is the way it is called in the "help" and in the code. Nevertheless I removed the word "log" from the new output.

[zenspider]

Failing on jruby-9.2 (but not head?!?)... I don't know from the output what is wrong and what is noise.

[zenspider]

@marcandre looks like:

2020-08-14T03:45:09.8966400Z Failure: test_ifelse(Racc::TestRaccCommand)
2020-08-14T03:45:09.9105454Z /home/runner/work/racc/racc/test/test_racc_command.rb:325:in `test_ifelse'
2020-08-14T03:45:09.9111513Z      322:     def test_ifelse
2020-08-14T03:45:09.9111899Z      323:       stderr = nil
2020-08-14T03:45:09.9112659Z      324:       racc "-o#{@TAB_DIR}/ifelse", "#{ASSET_DIR}/ifelse.y", stdout_filter: ->(s) { stderr = s }
2020-08-14T03:45:09.9112978Z   => 325:       assert_equal(<<~STDERR, stderr)
2020-08-14T03:45:09.9113213Z      326:         1 useless nonterminals:
2020-08-14T03:45:09.9113454Z      327:           dummy
2020-08-14T03:45:09.9134532Z      328:         2 useless rules:

it just goes for miles... nasty

[marcandre]

Rebased to include #139, should be green now...