Merge tag 'v0.17.0' into develop

0.17.0
Stop building against 0.11. The damn release fails half the time.
An attribute without prefix is outside all namespaces.
New test case.
Instead of having all walkers that accept "text" also accept "attributeValue", have AttributeWalker convert "attributeValue" events to "text" events. This fixes a bug in the parsing logic where an "attributeValue" event might be accepted by a <text/> appearing as element contents rather than as attribute value.
Dropped the ``Event.matchingEvents`` method since it is used nowhere.
Cleaned the code to use === and !== consistently.
Use Object.create(null) in the places where it makes sense.
Updated required versions.
Make parse.js a module so that we don't have to pay the expense of spawning a process.
Version bump.
Merge branch 'release/0.17.1'