V0.3.9

Just a quick corrective version over v0.3.7 to fix the behaviour of several untested features, like the newly added filters of for loops.
This release also introduces few more meta-expression operators to allow escaping, and a realistic example emitting HTML to complement the rest of the docs.

New features

• when as a prop command for the conditional rendering of the owner.

Breaking changes

• sort-by and order-by will now use | in place , to split multiple options.
• when/is fully replaced. The older syntax was dreadful but necessary without the RPN virtual machine, but now that we have… say hello to test/case.