new html5 schema with blackjack and extensions
SVG, MathML and RDFa are now supported
#WEB-462 fixed
#WEB-417 fixed
cleanup SVG and MathML hack
testdata corrected for new schema
xhtml should be valid, only body/head/frameset are permitted under html node
[github] IDEA-119693 Don't share workspace.xml

Filter out ignored & excluded files.
[diff] Don't create inner class for customizing action's icon
[vcs] Don't allow returning duplicate VirtualFiles

Previously the VirtualFile was actually duplicated for each
simple modification change (with both before- and after- revisions).

Relates to IDEA-119855.
[diff] remove unused
[diff] IDEA-119780 close dialogs with CANCEL exit code rather OK

Seems to be a more safe choice.
include only SVG-tiny
modifier fix should not contain psi refs