Add support to validate XML against XSD 1.1

[mkordas]

Currently method com.jcabi.xml.XSDDocument#validate uses XSD 1.0 parser. XSD 1.1 has couple of new features added, like possibility to require exactly one attribute out of two that will be useful in other Teamed projects.

I'd expect just to replace 1.0 parser with 1.1, as version 1.1 is just superset of 1.0.

[dmarkov]

@yegor256 please take a look at it and dispatch (see par.21)

[yegor256]

@mkordas but we're not using any specific parser. we're just using JDK. parser is provided in runtime. or I didn't get the problem?

[mkordas]

@yegor256 you are right! Do you think it is in scope of integration test, Javadoc or http://xml.jcabi.com/example-xsd.html to provide instruction how to enable XSD 1.1 parsing?

[yegor256]

@mkordas yes, let's document it

[dmarkov]

@mkordas thanks a lot for reporting, 15 mins added to your acc, pmt ID 56af291dc2680807d7000398

[mkordas]

@yegor256 actually I've realized that we may have to modify line https://github.com/jcabi/jcabi-xml/blob/master/src/main/java/com/jcabi/xml/XSDDocument.java#L158. We should set it to http://www.w3.org/XML/XMLSchema/v1.1 according to https://xerces.apache.org/xerces2-j/faq-xs.html

[longtimeago]

@yegor256 can we proceed here?

[longtimeago]

@yegor256 could you please respond to messages above?

[longtimeago]

@yegor256 ping :)

[longtimeago]

@yegor256 please, proceed here :)

[yegor256]

@dmarkov pls assign @westonized to this ticket

[dmarkov]

@dmarkov pls assign @westonized to this ticket

@yegor256 OK @westonized please proceed, this task is yours

[longtimeago]

@westonized any progress so far?