Enhance test suite

[tueda]

This PR depends on the first commit in #511, which improves the portability of the test suite script.

It resolves #580 by updating the Ruby minimum version to 2.0.0. It also improves --stat option (order of) output, word size detection for v5.0.0, and includes code refactoring.

Hopefully, later I would like to add some resolution for #581 (warning detection) and update the usage in the README file of the test suite (check/README.md), but this PR could be merged as-is.

[coveralls]

coverage: 50.735%. first build
when pulling b484d7b on tueda:pr-improve-test-suite-1
into 42de574 on vermaseren:master.

[tueda]

• Duplicated output_summary_marker in the output without the --stat option was fixed.
• The warning detection pattern was relaxed (to resolve Non-canonical warnings ignored in test cases #581).

Test failures are due to warnings in Issue95b and Issue563.

[tueda]

Does it make sense to implement #{(ruby expression)} and write, e.g.,

#:largesize #{threaded? && ncpu == 4 ? 450025600 : threaded? && ncpu == 2 ? 300025600 : 25600}

for Issue95b?

[jodavies]

Sorry, I thought I had checked for such warnings before, at least for 95b (for this one of course the test suite does not run with --without-zlib). For this one we can replace the test setup parameters with

#:filepatches       16
#:largepatches      20
#:maxtermsize      200
#:termsinsmall      16

and then one still has the crash before the fix, and it runs with no buffer size warnings.

For 563 we can just change SubTermsInSmall to 64. Probably this resize is why I settled on 65 as a good number of terms in the argument for the test anyway...

[jodavies]

Do you want to update the 95b and 563 buffer settings as part of this series, or as a separate PR?

[tueda]

I think I can include them. But it is also fine if you want to make a separate PR and merge it before this PR.

[jodavies]

You can put it in with this, next to/merged with the commit that changes the warning pattern.