Issue #451: Initial tests.
Issue #451: XmlParser-two_consecutive_br_limit tests: More and better.
Merge branch 'master' into issue_451
Correct variable names in XmlParser-two-consecutive-br-limit tests.
Merge branch 'master' into issue_451

Conflicts:
	src/test/unit/specific_feature_tests/xml_parser.js
`XmlParser-two_consecutive_br_limit` QUnit module: updated setup function.
Merge branch 'master' into issue_451
Parser: Allow at most two consecutive `br`s.
Parser: only-child-`br`-removal code is more reliable.
Fix two unit tests to correspond to new `br`-removal behavior.
`XhtmlSaxListener.closeBlockTag`: Add comment.
Changelog for issue #570.
Merge pull request #570 from wymeditor/issue_570

Parser to strip more than two consecutive line-breaks