vnu.jar options support

[sveetch]

Watch for available vnu.jar options and possibly add support for them.

Required

• User agent have to be supported since first release in another issue;
• Xss for java block allocation;
• no-stream is for rare cases to continue validation even with critical error;

Maybe

• css support may be interesting enough;
• svg may be;
• asciiquotes is for exotic usecases and lowest priority;
• option about html extension may not be very common case;
• filter options is to filter messages from regexes may be interesting but a rare case and not very simple to cover;

Won't do

• Format is not elligible since html_checker stands on JSON report only;
• error and exit code stuff is only managed internally in html_checker;
• no-langdetect is to avoid warning about missing lang attribute, i would prefer to keep this common warning since it is not advised to overrule it;

[sveetch]

Also i forgot to implement the -Xss for Java interpreter (did in validator class but seems it has been removed)

[sveetch]

Note, watch for using mockup to avoid executing interpreter and validator during tests of new arguments, we just need to ensure command line is ok.

https://docs.pytest.org/en/latest/monkeypatch.html

[sveetch]

Remember to write some help for every options

[sveetch]

Finished to implement required options, keep issue opened for the "maybe" ones for some time.