Added epub30-test-006-mathml and add dir="rtl" in Hebrew test
Merge branch 'master' of git://github.com/mgylling/epub-testsuite

Conflicts:
	content/30/epub30-test-004-he/EPUB/xhtml/display2.xhtml
	content/30/epub30-test-004-he/EPUB/xhtml/display4.xhtml
MathML tests