XSLDocument ctor must accept SystemId in most cases

See #191, release log:

• b29c4b2 by @yegor256: #191 extra ctors
• eb26703 by @yegor256: extra test
• d748626 by @renovate[bot]: Update dependency org.slf4j:sl...
• 9215cc5 by @renovate[bot]: Update dependency org.slf4j:sl...
• 4862828 by @renovate[bot]: Update dependency org.cactoos:...
• 2ed8ba7 by @renovate[bot]: Update dependency com.jcabi:jc...
• ffa3147 by @yegor256: new parent

Released by Rultor 2.0-SNAPSHOT, see build log